CN117553902A

CN117553902A - Multi-wavelength-based laser vibration meter and laser vibration measuring method

Info

Publication number: CN117553902A
Application number: CN202311857702.7A
Authority: CN
Inventors: 沈杨翊; 孔新新; 郝义伟; 戴玉; 张举; 张晓强; 伍洲; 张文喜
Original assignee: Aerospace Information Research Institute of CAS
Current assignee: Aerospace Information Research Institute of CAS
Priority date: 2023-12-29
Filing date: 2023-12-29
Publication date: 2024-02-13

Abstract

The disclosure relates to a multi-wavelength-based laser vibration meter and a laser vibration measuring method, which are applied to the technical field of laser measurement. The vibration meter includes: the laser generates first wavelength laser and second wavelength laser; a beam splitter for splitting the first wavelength laser and the second wavelength laser to obtain a first reference light to be modulated and a first detection light, and obtaining a second reference light to be modulated and a second detection light; the modulator is used for modulating the first reference light to be modulated and the second reference light to be modulated respectively to obtain first reference light and second reference light; a transmitter for transmitting first detection light and second detection light to the detected object, and receiving first reflection light obtained by reflecting the first detection light by the detected object and second reflection light obtained by reflecting the second detection light by the detected object; and the processor is used for obtaining first interference light according to the first reference light and the first reflected light, obtaining second interference light according to the second reference light and the second reflected light, and obtaining vibration amplitude information of the measured object by combining the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light.

Description

Multi-wavelength-based laser vibration meter and laser vibration measuring method

Technical Field

The present disclosure relates to the field of laser measurement technologies, and more particularly, to a laser vibration meter and a laser vibration measuring method based on multiple wavelengths.

Background

The laser vibration measurement technology is a high-precision interferometry technology and has wide application in the fields of quality control, reverse engineering, medical diagnosis, aerospace and the like.

The laser vibration measuring technology can send laser to an object to be measured through a laser vibration measuring instrument, the laser vibration measuring instrument receives reflected laser obtained through reflection of the object to be measured, and vibration amplitude information of the object to be measured is obtained according to the reflected laser and preset reference laser.

In the course of implementing the present disclosure, it was found that the accuracy of the vibration amplitude information was low.

Disclosure of Invention

The disclosure provides a laser vibration meter and a laser vibration measuring method based on multiple wavelengths.

According to one aspect of the present disclosure, there is provided a laser vibrometer comprising:

a laser configured to generate laser light, wherein the laser light includes a first wavelength laser light and a second wavelength laser light;

the beam splitter is configured to split the first wavelength laser to obtain first reference light to be modulated and first detection light, and split the second wavelength laser to obtain second reference light to be modulated and second detection light;

The modulator is configured to modulate the first reference light to be modulated to obtain first reference light, and modulate the second reference light to be modulated to obtain second reference light;

a transmitter configured to transmit the first probe light and the second probe light to a subject, and to receive a first reflected light of the first probe light reflected by the subject and a second reflected light of the second probe light reflected by the subject; and

and the processor is configured to obtain first interference light according to the first reference light and the first reflected light, obtain second interference light according to the second reference light and the second reflected light, and obtain vibration amplitude information of the measured object according to the combination of first vibration amplitude information of the measured object corresponding to the first interference light and second vibration amplitude information of the measured object corresponding to the second interference light.

According to an embodiment of the present disclosure, the transmitter includes:

a fiber optic circulator including a first end, a second end, and a third end configured to:

receiving the first detection light and the second detection light through the first end;

Transmitting the first detection light and the second detection light to the tested object through the second end;

receiving, by the second end, a first reflected light obtained by reflecting the first probe light by the object to be measured and a second reflected light obtained by reflecting the second probe light by the object to be measured; and

and transmitting the first reflected light and the second reflected light to the processor through the third end. According to an embodiment of the present disclosure, the transmitter includes:

a first point diffractive fiber optic circulator including a fourth end, a fifth end, a sixth end, a polarizer, a first mirror, and a first polarizing beamsplitter configured to:

receiving the first probe light and the second probe light through the fourth end;

the polarization states of the first detection light and the second detection light are adjusted through the polarizer, so that first polarization detection light and second polarization detection light are obtained;

the first polarized detection light and the second polarized detection light are reflected to the first polarized spectroscope through the first reflecting mirror;

transmitting the first polarized detection light and the second polarized detection light to the object to be measured through the fifth end when the first polarized detection light and the second polarized detection light are reflected by the first polarized spectroscope, wherein the first polarized detection light is reflected by the object to be measured to obtain the first reflected light, the second polarized detection light is reflected by the object to be measured to obtain the second reflected light, and the first reflected light and the second reflected light are received through the fifth end; and

And transmitting the first reflected light and the second reflected light to the processor through the sixth end when the first polarization beam splitter transmits the first reflected light and the second reflected light.

According to an embodiment of the present disclosure, the transmitter includes:

a third point diffractive optical fiber circulator including a tenth end, a twelfth end, a second polarizing beamsplitter, a second mirror, and a 1/4 wave plate configured to:

receiving the first detection light and the second detection light through the tenth end;

reflecting the first detection light and the second detection light to the second polarization beam splitter through the second reflecting mirror;

the polarization states of the first detection light and the second detection light reflected by the second polarization spectroscope are adjusted through the 1/4 wave plate, so that first circular polarization detection light and second circular polarization detection light are obtained respectively;

transmitting the first circular deflection detection light and the second circular deflection detection light to the measured object through the eleventh end, and receiving first reflected light obtained by reflecting the first circular deflection detection light by the measured object and second reflected light obtained by reflecting the second circular deflection detection light by the measured object through the tenth end;

Under the condition that the tenth end receives the first reflected light and the second reflected light, the polarization states of the first reflected light and the second reflected light are adjusted through the 1/4 wave plate, so that first polarized reflected light and second polarized reflected light are obtained;

transmitting the first polarized reflected light and the second polarized reflected light to the twelfth end through the second polarizing beam splitter; and

transmitting the first polarized reflected light and the second polarized reflected light to the processor via the twelfth end.

According to an embodiment of the present disclosure, the above processor is further configured to:

calculating first vibration amplitude information including first speckle information from the frequency information of the first interference light, and calculating second vibration amplitude information including second speckle information from the frequency information of the second interference light;

and carrying out weighted superposition on the differential result of the first vibration amplitude information and the differential result of the second vibration amplitude information, and integrating the weighted superposition calculation result to obtain the vibration amplitude information for suppressing the first speckle information and the second speckle information.

According to an embodiment of the present disclosure, the multi-wavelength-based laser vibration meter further includes:

And a lens disposed between the transmitter and the object to be measured, configured to collect the first probe light and the second probe light, collect the first reflected light of the first probe light, and collect the second reflected light.

According to another aspect of the embodiments of the present disclosure, there is provided a multi-wavelength-based laser vibration measuring method, including:

the laser generates laser light, wherein the laser light comprises first wavelength laser light and second wavelength laser light;

the beam splitter splits the first wavelength laser to obtain first reference light to be modulated and first detection light, and splits the second wavelength laser to obtain second reference light to be modulated and second detection light;

the modulator modulates the first reference light to be modulated to obtain first reference light, and modulates the second reference light to be modulated to obtain second reference light;

the transmitter transmits the first detection light and the second detection light to the detected object, and receives first reflection light obtained by reflecting the first detection light by the detected object and second reflection light obtained by reflecting the second detection light by the detected object; and

the processor obtains first interference light according to the first reference light and the first reflected light, obtains second interference light according to the second reference light and the second reflected light, and combines to obtain vibration amplitude information of the measured object according to first vibration amplitude information of the measured object corresponding to the first interference light and second vibration amplitude information of the measured object corresponding to the second interference light.

According to an embodiment of the present disclosure, the combining the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light to obtain the vibration amplitude information of the measured object includes:

According to the technical scheme of the embodiment of the disclosure, a laser vibration meter and a laser vibration measuring method are provided, vibration amplitude information of a measured object is obtained through first interference light and second interference light, the first interference light can be obtained through first reflection light and first reference light which are obtained through reflection of first detection light by the measured object, and the first detection light and the first reference light are obtained through beam splitting of first wavelength laser; the second interference light may be obtained by a second reflected light obtained by reflecting the second detection light by the object to be measured and a second reference light obtained by splitting the second detection light and the second reference light by a second wavelength laser; the first interference light carries vibration amplitude information of the measured object, the second interference light carries vibration amplitude information of the measured object, and multiple detection is carried out on the vibration amplitude information of the measured object by jointly analyzing the first interference light and the second interference light, so that accuracy of the vibration amplitude information of the measured object is improved.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of the embodiments of the present disclosure with reference to the accompanying drawings in which.

Fig. 1 shows a schematic structural diagram of a laser vibration meter according to an embodiment of the present disclosure.

Fig. 2 shows a schematic structural diagram of a laser according to an embodiment of the present disclosure.

Fig. 3 shows a schematic structural diagram of a beam splitter according to an embodiment of the present disclosure.

Fig. 4 shows a schematic structural diagram of a modulator according to an embodiment of the present disclosure.

Fig. 5A shows a schematic structural diagram of a first point diffractive fiber optic circulator, according to an embodiment of the disclosure.

Fig. 5B shows a schematic structural diagram of a second point-diffractive fiber optic circulator, according to an embodiment of the disclosure.

Fig. 5C shows a schematic structural diagram of a third point diffractive fiber optic circulator, according to an embodiment of the disclosure.

Fig. 6 shows a schematic view of an optical path of a laser vibrometer according to a specific embodiment of the present disclosure.

Fig. 7 shows a flow diagram of a laser vibration measurement method according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is only exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the concepts of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

All terms (including technical and scientific terms) used herein have the commonly understood meaning unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.

Where expressions like at least one of "A, B and C, etc. are used, the expressions should be interpreted in a general sense as commonly understood (e.g.," a system having at least one of A, B and C "shall include, but not be limited to, a system having a alone, B alone, C alone, a and B, a and C, B and C, and/or A, B, C, etc.). Where expressions like "at least one of A, B or C, etc." are used, this expression should generally be interpreted in the sense which is commonly understood (e.g. "a system with at least one of A, B or C" shall include, but not be limited to, a system with a alone, B alone, C alone, a and B, a and C with a and C, B and C with A, B, C, etc.).

In the technical scheme of the disclosure, the related processes of data collection, storage, use, processing, transmission, provision, disclosure, application and the like all conform to the regulations of related laws and regulations, necessary security measures are taken, and the public order harmony is not violated.

In the technical solution of the present disclosure, authorization or consent is obtained before the data involved is obtained or acquired.

The laser vibration meter sends laser to the object to be measured, receives reflected laser obtained by reflecting the laser by the object to be measured, and the reflected laser interferes with preset reference laser to obtain interference light. Since the parameter of the interference light can characterize the frequency information corresponding to the velocity of the object to be measured, the vibration amplitude information of the object to be measured can be obtained from the frequency information.

In the process of realizing the inventive concept, it is found that the reflected laser is affected by the surface roughness of the measured object, so that the reflected laser cannot be totally reflected back to the laser vibration meter, thereby affecting the accuracy of the reflected laser and thus the accuracy of vibration amplitude information.

To this end, the present disclosure provides a laser vibrometer comprising: the laser is configured to generate laser light, wherein the laser light includes a first wavelength laser light and a second wavelength laser light. The beam splitter is configured to split the first wavelength laser to obtain first reference light to be modulated and first detection light, and split the second wavelength laser to obtain second reference light to be modulated and second detection light. The modulator is configured to modulate the first reference light to be modulated to obtain first reference light, and modulate the second reference light to be modulated to obtain second reference light. The transmitter is configured to transmit the first detection light and the second detection light to the object to be measured, and to receive the first reflected light obtained by reflecting the first detection light by the object to be measured and the second reflected light obtained by reflecting the second detection light by the object to be measured. The processor is configured to obtain first interference light according to the first reference light and the first reflected light, obtain second interference light according to the second reference light and the second reflected light, and combine first vibration amplitude information of the measured object corresponding to the first interference light and second vibration amplitude information of the measured object corresponding to the second interference light to obtain vibration amplitude information of the measured object.

As shown in fig. 1, the laser vibrometer 100 may include a laser 110, a beam splitter 120, a modulator 130, a transmitter 140, and a processor 150.

The laser 110 may be configured to generate laser light, wherein the laser light includes a first wavelength laser light and a second wavelength laser light.

The beam splitter 120 may be configured to split the first wavelength laser to obtain a first reference light to be modulated and a first detection light, and split the second wavelength laser to obtain a second reference light to be modulated and a second detection light.

The modulator 130 may be configured to modulate the first reference light to be modulated to obtain a first reference light, and modulate the second reference light to be modulated to obtain a second reference light.

The transmitter 140 may be configured to transmit the first detection light and the second detection light to the object to be measured outside the laser vibrometer 100, and to receive the first reflected light obtained by reflecting the first detection light by the object to be measured and the second reflected light obtained by reflecting the second detection light by the object to be measured.

The processor 150 may be configured to obtain first interference light according to the first reference light and the first reflected light, obtain second interference light according to the second reference light and the second reflected light, and obtain vibration amplitude information of the measured object according to first vibration amplitude information of the measured object corresponding to the first interference light and second vibration amplitude information of the measured object corresponding to the second interference light.

According to the embodiments of the present disclosure, since the first wavelength laser light and the second wavelength laser light are not single wavelength lasers due to the limitation of the lasers, in the case where the wavelength difference between the first wavelength laser light and the second wavelength laser light is too small, there is an overlapping band of the first wavelength laser light and the second wavelength laser light, resulting in interference of the first wavelength laser light and the second wavelength laser light. In order to effectively ensure that the first wavelength laser and the second wavelength laser do not interfere, the wavelength difference between the first wavelength laser and the second wavelength laser can be larger than or equal to a preset threshold value. The preset threshold may be configured according to actual service requirements, which is not limited herein. For example, the preset threshold may be 8nm.

According to embodiments of the present disclosure, beam splitter 120 may partially transmit and partially reflect a light beam input to beam splitter 120, thereby achieving beam splitting of an incident light beam.

According to the embodiment of the present disclosure, the first reference light to be modulated and the first probe light may be obtained from the first wavelength laser light through the beam splitter 120, and the first reference light to be modulated is not transmitted to the object to be measured together with the first probe light. The beam splitter 120 can obtain the second reference light to be modulated and the second detection light from the second wavelength laser, and the second reference light to be modulated is not transmitted to the object to be measured together with the first detection light.

According to the embodiment of the disclosure, after the first reference light to be modulated passes through the modulator 130, the optical parameter of the first reference light to be modulated is modulated to generate the first reference light, and the optical parameter of the first reference light can enable the first reference light to meet the interference condition of interference with the first reflected light, so that the first interference light can be obtained according to the first reference light and the first reflected light. After the second reference light to be modulated passes through the modulator 130, optical parameters of the second reference light to be modulated are modulated to generate second reference light, and the optical parameters of the second reference light can enable the second reference light to meet an interference condition of interference with second reflected light, so that second interference light can be obtained according to the second reference light and the second reflected light.

According to an embodiment of the present disclosure, the object to be measured may be an object including vibration amplitude information, and in a case where the transmitter 140 transmits the first probe light to the object to be measured and the object to be measured reflects the first probe light to obtain the first reflected light, the first reflected light may carry the vibration amplitude information of the object to be measured back to the transmitter 140. In the case where the transmitter 140 transmits the second probe light to the object to be measured, and the object to be measured reflects the second probe light to obtain second reflected light, the second reflected light may return to the transmitter 140 with vibration amplitude information of the object to be measured.

According to the embodiment of the disclosure, in a scene which is difficult to detect in practice, the detected object is detected by the first detection light and the second detection light, and the vibration amplitude information of the detected object can be obtained more conveniently by combining the first vibration amplitude information of the detected object corresponding to the first interference light and the second vibration amplitude information of the detected object corresponding to the second interference light. For example, in a scene where it is difficult to set a detection device in the field, such as in the geological field, to survey seismic waves, vibration amplitude information of a measured object can be obtained conveniently by laser vibration measurement. For example, when detecting an object unsuitable for contact detection such as a precision device, laser vibration measurement can obtain vibration amplitude information of the object without contacting the object.

According to the embodiment of the disclosure, after the laser 110 generates the first wavelength laser light and the second wavelength laser light, the beam splitter 120 splits the first wavelength laser light to obtain the first reference light to be modulated and the first detection light, and splits the second wavelength laser light to obtain the second reference light to be modulated and the second detection light. The transmitter 140 transmits the first probe light and the second probe light to the object to be measured, so that the first probe light and the second probe light return to the transmitter 140 after the object to be measured contacts and the vibration amplitude information of the object to be measured is carried. The transmitter 140 receives the first reflected light obtained by reflecting the first probe light by the object to be measured and the second reflected light obtained by reflecting the second probe light by the object to be measured, and then transmits the first reflected light and the second reflected light to the processor 150. The modulator 130 modulates the first reference light to be modulated and the second reference light to be modulated, respectively, to obtain a first reference light and a second reference light, and sends the first reference light and the second reference light to the processor 150.

According to an embodiment of the disclosure, after obtaining the first interference light and the second interference light, the processor 150 may obtain optical parameters of the first interference light and the second interference light, where the optical parameters of the first interference light may represent information carried by the first interference light, and the information carried by the first interference light may include vibration amplitude information of the measured object; the optical parameter of the second interference light may represent information carried by the second interference light, and the information carried by the second interference light may include vibration amplitude information of the measured object. Therefore, under the condition of combining the first interference light and the second interference light for analysis, the vibration amplitude information of the measured object carried by the interference light with different wavelengths can be analyzed, so that the accuracy of the laser vibration meter 100 is improved. For example, by combining the first vibration amplitude information of the object to be measured corresponding to the first interference light and the second vibration amplitude information of the object to be measured corresponding to the second interference light, noise information in the first vibration amplitude information and the second vibration amplitude information is suppressed, and final vibration amplitude information is obtained.

According to the embodiment of the disclosure, vibration amplitude information of a measured object is obtained through first interference light and second interference light, wherein the first interference light can be obtained through first reflection light and first reference light which are obtained through reflection of first detection light by the measured object, and the first detection light and the first reference light are obtained through beam splitting of first wavelength laser; the second interference light may be obtained by a second reflected light obtained by reflecting the second detection light by the object to be measured and a second reference light obtained by splitting the second detection light and the second reference light by a second wavelength laser; the first interference light carries vibration amplitude information of the measured object, the second interference light carries vibration amplitude information of the measured object, and multiple detection is carried out on the vibration amplitude information of the measured object by jointly analyzing the first interference light and the second interference light, so that accuracy of the vibration amplitude information of the measured object is improved.

In embodiments of the present disclosure, a processor may be a generalized description of a plurality of devices in aggregate. For example, the processor includes a wavelength division multiplexer, a detector, and an upper computer. The host computer may be a computer device.

The first reflected light and the second reflected light of different wavelengths are mixed in the same reflected light beam before entering the wavelength division multiplexer. After receiving the reflected light beam, the wavelength division multiplexer distinguishes the first reflected light and the second reflected light in the reflected light beam. And combining the first reflected light with the first wavelength with the first reference light, and combining the second reflected light with the second reference light with the second wavelength, so that the first reflected light and the first reference light form first interference light, and the second reflected light and the second reference light form second interference light.

The first detector is used for detecting the first interference light and transmitting information of the detected first interference light to the upper computer; the second detector is used for detecting the second interference light and transmitting information of the detected second interference light to the upper computer. And the upper computer combines the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light to obtain the vibration amplitude information of the measured object.

As shown in fig. 2, the laser 210 may include a first laser 211 and a second laser 212.

The first laser 211 is configured to generate a first wavelength laser light.

The second laser 212 is configured to generate a second wavelength laser light.

According to embodiments of the present disclosure, two lasers may be provided to generate a first wavelength laser light and a second wavelength laser light, respectively. The laser may be any one of a solid state laser, a gas laser, a dye laser, a semiconductor laser, a fiber laser, and a free electron laser, and the disclosure is not limited thereto.

As shown in fig. 3, beam splitter 320 may include a first beam splitter 321 and a second beam splitter 322.

The first beam splitter 321 is configured to split the first wavelength laser light to obtain a first reference light to be modulated and a first detection light.

And a second beam splitter 322 configured to split the second wavelength laser light to obtain a second reference light to be modulated and a second probe light.

According to embodiments of the present disclosure, one light beam may be split into two or more light beams by a beam splitter. The two or more beams of light obtained by beam splitting by the beam splitter may be reflected light or transmitted light of one beam of light split, and the split ratio of the reflected light and the transmitted light may vary as a function of the wavelength of the incident light, and may also vary as the beam splitter material varies.

According to an embodiment of the present disclosure, the first wavelength laser light and the second wavelength laser light are different in wavelength, and the first beam splitter 321 and the second beam splitter 322 may be provided to split the first wavelength laser light and the second wavelength laser light, respectively.

According to an embodiment of the present disclosure, since the first interference light may be obtained from the first reflected light and the first reference light, and the second interference light may be obtained from the second reflected light and the second reference light, in order to secure the interference effect of the first interference light and the second interference light, the split ratio of the first beam splitter 321 and the second beam splitter 322 may be set to 1:1.

according to an embodiment of the present disclosure, the first beam splitter 321 and the second beam splitter 322 may select any one of a metal film beam splitter and a dielectric film beam splitter, and the present disclosure is not limited herein.

As shown in fig. 4, the modulator 430 may include a first modulator 431 and a second modulator 432.

The first modulator 431 is configured to modulate the first reference light to be modulated, so as to obtain first reference light.

The second modulator 432 is configured to modulate the second reference light to be modulated to obtain second reference light.

According to an embodiment of the present disclosure, the first reference light is obtained by modulating the first reference light to be modulated. The optical parameter of the first reference light meets a preset condition, so that interference with the first reflected light can be caused, and first interference light is obtained.

According to the embodiments of the present disclosure, the polarization state, initial phase, etc. of the first reference light may be modulated such that the first reference light satisfies a coherence condition under which the first reflected light interferes, thereby obtaining the first interference light.

According to an embodiment of the present disclosure, the amplitude of the first reference light may also be modulated so that the amplitude of the first interference light obtained from the first reference light and the first reflected light also satisfies a preset condition.

According to the embodiment of the disclosure, the preset condition satisfied by the second reference light may refer to the condition satisfied by the first reference light, which is not described herein.

According to an embodiment of the present disclosure, the first reference light to be modulated and the second reference light to be modulated are modulated in order to meet a preset condition for the corresponding obtained first interference light and second interference light, so as to obtain vibration amplitude information of the measured object, and a person skilled in the art may modulate the first reference light to be modulated and the second reference light to be modulated in various manners, which is not limited herein.

According to an embodiment of the present disclosure, the first modulator 431 and the second modulator 432 may select any one of a phase modulator, a frequency modulator, an amplitude modulator, a double sideband modulator, a single sideband modulator, and a vestigial sideband modulator, which is not limited herein.

According to embodiments of the present disclosure, the transmitter may include a fiber optic circulator. The fiber optic circulator includes a first end, a second end, and a third end.

The first probe light and the second probe light are received through the first end. And sending the first detection light and the second detection light to the measured object through the second end. The second end receives first reflected light obtained by reflecting the first detection light by the tested object and second reflected light obtained by reflecting the second detection light by the tested object. The first reflected light and the second reflected light are transmitted through a third end-to-end processor.

According to the embodiment of the disclosure, the three-terminal structure of the optical fiber circulator realizes the isolation of the light of the input end and the light of the output end. For example, the first end of the optical fiber circulator receives the first detection light and the second detection light and then outputs the first detection light and the second detection light through the second end of the optical fiber circulator, and the first reflection light obtained by reflecting the first detection light through the measured object and the second reflection light obtained by reflecting the second detection light through the measured object are not output from the first end of the optical fiber circulator but output through the third end of the optical fiber circulator, thereby realizing the isolation of the first detection light and the first reflection light and the isolation of the second detection light and the second reflection light. Reducing mutual interference between lasers of the same wavelength.

As shown in fig. 5A, the transmitter may include a first point diffractive fiber optic circulator 540. The first point diffraction fiber circulator 540 can include a fourth end 541, a fifth end 544, a sixth end 546, a polarizer 542, a first polarizing beamsplitter 543, and a first mirror 545.

The first probe light and the second probe light are received through the fourth terminal 541. The polarization states of the first detection light and the second detection light are adjusted by the polarizer 542, resulting in the first polarization detection light and the second polarization detection light. In the case where the first polarization beam splitter 543 transmits the first polarization detection light and the second polarization detection light, the transmitted first polarization detection light and second polarization detection light are transmitted to the object to be measured through the fifth end 544, and the first reflected light obtained by reflecting the first polarization detection light by the object to be measured and the second reflected light obtained by reflecting the second polarization detection light by the object to be measured are received through the fifth end 544.

In the case where the first polarization beam splitter 543 reflects the first reflected light and the second reflected light, the first reflected light and the second reflected light are reflected by the first reflecting mirror 545. The first reflected light and the second reflected light are sent to the processor through a sixth end 546.

The chamfer surface of the first polarization beam splitter 543 is plated with a semi-transparent and semi-reflective film so that the first polarization beam splitter 543 transmits the first polarization detection light and the second polarization detection light, and reflects the first reflection light and the second reflection light.

According to an embodiment of the present disclosure, after the first detection light and the second detection light pass through the polarizer 542, the first detection light and the second detection light obtain polarization states, i.e., the first polarization detection light and the second polarization detection light, respectively, so that the first polarization detection light and the second polarization detection light can be transmitted through the first polarization beam splitter 543, thereby reaching the object to be measured through the fifth end 544. The first reflected light obtained by reflecting the first polarized detection light by the object to be measured and the second reflected light obtained by reflecting the second polarized detection light by the object to be measured have opposite polarization states to those of the first detection light and the second detection light, and thus, the first reflected light and the second reflected light are reflected at the polarizing beam splitter 543, reach the reflecting mirror 545, and are emitted to the sixth end 546 again.

According to the embodiment of the disclosure, micro small holes with wavelengths close to those of the first detection light and the second detection light are formed at the fourth end 541, the fifth end 544 and the sixth end 546, so that the first detection light and the second detection light generate ideal spherical wave fronts, influence of wave front disturbance caused by parallel light beams formed by laser emission Gaussian beams or collimating lenses on subsequent interference is eliminated, and energy loss of the first detection light and the second detection light at polarizing devices such as a polarizer 542 and a polarizing beam splitter 543 is reduced. The polarizer 542, the polarizing beam splitter 543 and the reflecting mirror 545 are configured such that the end face of the receiving optical fiber is parallel to the optical fiber for transmitting the first detection light and the second detection light, so that the optical paths of the first detection light and the second detection light corresponding to the optical path from the fourth end 541 to the polarizing beam splitter 543 are equal to the optical paths of the first reflection light and the second reflection light corresponding to the optical path from the sixth end 546 to the polarizing beam splitter 543, so that the fourth end 541 and the sixth end 546 of the point diffraction optical fiber circulator 540 are conjugate, and further, an additional phase caused by the suppression of the optical path variation can be realized, the beam quality of the first detection light and the second detection light corresponding to each other is improved, and the generation of extra stray light except the first detection light and the second detection light is avoided.

As shown in fig. 5B, the transmitter may include a second point diffractive fiber optic circulator 550. The second point diffractive fiber optic circulator 550 can include a seventh end 551, an eighth end 555, a ninth end 556, and a prism assembly. The prism group includes triangular prism 552, parallelogram prism 553, and trapezoidal prism 554.

The first and second detection light may enter the prism group through the seventh end 551.

The first probe light and the second probe light first enter the parallelogram prism 553, and the first contact surface with the parallelogram prism 553 is the first side surface of the parallelogram prism 553, namely the left side surface of the parallelogram prism 553 in fig. 5B. The first side of the parallelogram prism 553 may be coated with a polarizing film for adjusting the polarization states of the first and second probe lights to obtain third and fourth polarization probe lights.

The contact surface between the parallelogram prism 553 and the triangle prism 552 is a second side surface, and a reflective film structure is included between the triangle prism and the second side surface of the parallelogram prism for reflecting the obtained third polarized detection light and the fourth polarized detection light to the other surface parallel to the second side surface in the parallelogram prism 553, namely a third side surface. A semi-transparent and semi-reflective film structure is also disposed between the third side of the parallelogram prism 553 and the trapezoid prism 554, and is used for continuously reflecting the third polarized detection light and the fourth polarized detection light reflected to the third side to the eighth end 555; the transflective film structure is further configured to transmit the first reflected light and the second reflected light incident from the eighth end 555 to the trapezoidal prism 554, and to the ninth end 556 via the trapezoidal prism 554.

As shown in fig. 5C, the transmitter may include a third point diffractive fiber optic circulator 560. The third point diffraction fiber circulator 560 can include a tenth end 561, a tenth end 565, a twelfth end 566, a second mirror 562, a second polarizing beamsplitter 563, and a 1/4 wave plate 564.

The tenth end 561 is for receiving the first and second detection light and transmitting the first and second detection light to the second mirror 562. The second mirror 562 reflects the first detection light and the second detection light to the second polarization beam splitter 563.

The second polarization beam splitter 563 is provided with a transflective film. On the one hand, the second polarization beam splitter 563 is for reflecting the first detection light and the second detection light reflected by the second mirror 562 to the 1/4 wave plate 564. The 1/4 wave plate 564 adjusts the polarization states of the first detection light and the second detection light to obtain a first circularly polarized detection light and a second circularly polarized detection light, respectively; and transmits the first circular bias detection light and the second circular bias detection light to the eleventh end 565. The eleventh end 565 receives the first reflected light of the first circular polarization detection light reflected by the object to be measured and the second reflected light of the second circular polarization detection light reflected by the object to be measured. On the other hand, the first reflected light and the second reflected light entering through the eleventh end 565 pass through the 1/4 wave plate 564 to obtain first polarized reflected light and second polarized reflected light of which polarization states are adjusted. The second polarizing beamsplitter 563 transmits the first polarized reflected light and the second polarized reflected light to the twelfth end 566.

According to the embodiment of the disclosure, the seventh end 551, the eighth end 555, the ninth end 556, the tenth end 561, the tenth end 565, and the twelfth end 566 function in the same manner as the fourth end 541, the fifth end 544, and the sixth end 546, and are all used to generate the ideal spherical wave fronts of the first detection light and the second detection light, eliminate the influence of the wave front disturbance caused by the parallel light beam formed by the laser output gaussian beam or the collimating lens on the subsequent interference, and reduce the energy loss of the first detection light and the second detection light at the polarization state adjusting device such as the prism set or the polarization beam splitter. The prism group in the second point diffraction circulator 550, the second reflecting mirror in the third point diffraction circulator 560, the second polarizing beam splitter and the 1/4 wave plate are all used for guaranteeing that the optical path entering the detection light point diffraction circulator is equal to the optical path of the reflected light entering the point diffraction circulator, so that the additional phase caused by the change of the optical path is restrained, the beam quality corresponding to the first detection light and the second detection light is improved, and the generation of extra stray light except the first detection light and the second detection light is avoided. According to an embodiment of the present disclosure, the processor may be further configured to:

According to the first interference light, first speckle information is obtained, according to the second interference light, second speckle information is obtained, error information is obtained according to the first speckle information and the second speckle information, and vibration amplitude information of the measured object is obtained according to the first interference light, the second interference light and the error information.

According to the embodiment of the disclosure, after receiving the first reference light and the first interference light obtained by the first reflected light, the processor may obtain a first interference electric signal by using the photoelectric converter, may also obtain a second interference electric signal by using the photoelectric converter after receiving the second reference light and the second interference light obtained by using the second reflected light, may obtain first speckle information by analyzing the first interference electric signal, may obtain second speckle information by analyzing the second interference electric signal, may correspondingly suppress the error information after obtaining the error information according to the first speckle information and the second speckle information, and may thus obtain vibration amplitude information of the measured object.

Specifically, the upper computer in the processor can obtain first speckle information according to the first interference light, obtain second speckle information according to the second interference light, obtain error information according to the first speckle information and the second speckle information, and obtain vibration amplitude information of the measured object according to the first interference light, the second interference light and the error information.

According to the embodiment of the disclosure, under the condition of actual detection, a certain roughness exists on the surface of the detected object, so that under the condition that the first detection light and the second detection light reflect on the surface of the detected object, the obtained first reflection light and second reflection light do not return to the laser vibration meter strictly according to the original light paths of the first detection light and the second detection light, and therefore, the first reflection light can have first speckle information and the second reflection light can have second speckle information.

According to the embodiment of the disclosure, vibration amplitude information of a measured object is obtained through first interference light and second interference light, wherein the first interference light can be obtained through first reflection light and first reference light which are obtained through reflection of first detection light by the measured object, and the first detection light and the first reference light are obtained through beam splitting of first wavelength laser; the second interference light may be obtained by a second reflected light obtained by reflecting the second detection light by the object to be measured and a second reference light obtained by splitting the second detection light and the second reference light by a second wavelength laser; the first interference light carries vibration amplitude information of the measured object and first speckle information of the first detection light after being reflected by the measured object, the second interference light carries vibration amplitude information of the measured object and second speckle information of the second detection light after being reflected by the measured object, and the first speckle information and the second speckle information are restrained by joint analysis of the first interference light and the second interference light, so that accuracy of vibration amplitude information of the measured object is improved.

As shown in fig. 6, in the case of practical application of the laser vibration meter, the laser vibration meter may include a first laser 611, a second laser 612, a first beam splitter 621, a second beam splitter 622, a first modulator 631, a second modulator 632, a point diffraction fiber circulator 640, a lens 650, a wavelength division multiplexer 660, a first detector 671, a second detector 672, and a host computer 680.

The first laser 611 is configured to generate a first wavelength laser light, and split the first wavelength laser light into a first reference light to be modulated and a first probe light via the first beam splitter 621. The first modulator 631 may modulate the first reference light to be modulated to obtain the first reference light.

The second laser 612 is configured to generate a second wavelength laser light, and split the second wavelength laser light into a second reference light to be modulated and a second probe light via the second beam splitter 622. The second modulator 632 may modulate the second reference light to be modulated to obtain a second reference light.

Since the optical paths of the first probe light and the second probe light are the same in the point diffraction optical fiber circulator 640, the first probe light and the second probe light are coincident in the point diffraction optical fiber circulator 640 after simultaneously entering the point diffraction optical fiber circulator 640. The first probe light and the second probe light are output from the point diffraction fiber circulator 640, converged by the lens 650, and transferred to the object under test. The first reflected light obtained by reflecting the first probe light by the object to be measured and the second reflected light obtained by reflecting the second probe light by the object to be measured pass through the point diffraction optical fiber circulator 640 and then enter the wavelength division multiplexer 660. Wherein the first reflected light and the second reflected light are mixed into one reflected light beam, which passes through the point diffraction fiber circulator 640 and enters the wavelength division multiplexer 660.

In addition, the wavelength division multiplexer 660 may also receive the first reference light output from the first modulator 631 and the second reference light output from the second modulator 632.

The wavelength division multiplexer 660, upon receiving a reflected light beam in which the first reflected light and the second reflected light are mixed, first distinguishes the first reflected light and the second reflected light in the reflected light beam. And combining the first reflected light with the first wavelength with the first reference light, and combining the second reflected light with the second reference light with the second wavelength, so that the first reflected light and the first reference light form first interference light, and the second reflected light and the second reference light form second interference light. After combining the first interference light and the second interference light, the wavelength division multiplexer 660 transmits the first interference light to the first detector 671 and the second interference light to the second detector 672, so that the first detector 671 and the second detector 672 collect information of the first interference light and the second interference light, respectively, and transmit the information to the upper computer 680.

As shown in fig. 7, the laser vibration measuring method 700 may include operations S710 to S750.

In operation S710, a laser generates laser light, wherein the laser light includes a first wavelength laser light and a second wavelength laser light.

In operation S720, the beam splitter splits the first wavelength laser to obtain the first reference light to be modulated and the first detection light, and splits the second wavelength laser to obtain the second reference light to be modulated and the second detection light.

In operation S730, the modulator modulates the first reference light to be modulated to obtain a first reference light, and modulates the second reference light to be modulated to obtain a second reference light.

In operation S740, the transmitter transmits the first and second probe lights to the object to be measured, and receives the first reflected light obtained by reflecting the first probe light by the object to be measured and the second reflected light obtained by reflecting the second probe light by the object to be measured.

In operation S750, the processor obtains a first interference light according to the first reference light and the first reflected light, obtains a second interference light according to the second reference light and the second reflected light, and obtains vibration amplitude information of the measured object by combining the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light.

According to the embodiment of the disclosure, first reference light to be modulated and first detection light are obtained through first wavelength laser, first reference light is obtained through the first reference light to be modulated, first reflection light is obtained through the first detection light, wherein the first reflection light carries first speckle information and first vibration amplitude information of the measured object, and first interference light is obtained through the first reference light and the first reflection light. Obtaining second reference light to be modulated and second detection light through second wavelength laser, obtaining second reference light through the second reference light to be modulated, obtaining second reflection light through the second detection light, wherein the second reflection light carries second speckle information and second vibration amplitude information of the measured object, and obtaining second interference light through the second reference light and the second reflection light. The first speckle information and the second speckle information can be restrained by jointly processing the first interference light and the second interference light, and the accuracy of the vibration amplitude information of the measured object is improved.

According to an embodiment of the present disclosure, in operation S750, according to the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light, combining to obtain the vibration amplitude information of the measured object may include:

first vibration amplitude information including first speckle information is obtained from the first interference light. And obtaining second vibration amplitude information including second speckle information according to the second interference light. And obtaining vibration amplitude information of the measured object according to the first vibration amplitude information and the second vibration amplitude information.

According to an embodiment of the present disclosure, noise may exist outside the laser vibrometer 100, and external noise may participate in a process of obtaining first reflected light from first probe light and may also participate in a process of obtaining second reflected light from second probe light, and thus, parameters related to external noise exist in the parametric expressions of the first interference light and the second interference light.

According to the embodiments of the present disclosure, in the case where the first vibration amplitude information is obtained from the first interference light, the first speckle information may be obtained from the first interference light and the parameter related to the external noise, and in the same manner, in the case where the second vibration amplitude information is obtained from the second interference light, the second speckle information may be obtained from the second interference light and the parameter related to the external noise.

According to the embodiment of the disclosure, the first vibration amplitude information and the second vibration amplitude information are weighted and overlapped, so that the first speckle information and the second speckle information can be restrained, and the vibration amplitude information of the vibration information of the measured object can be obtained.

According to the embodiment of the disclosure, since the first speckle information and the second speckle information can be obtained by parameters related to external noise, partial cancellation can be realized after the first speckle information and the second speckle information are overlapped by weighting and then overlapping the first vibration amplitude information and the second vibration amplitude information, that is, the first speckle information and the second speckle information are reduced, thereby realizing that the first speckle information and the second speckle information caused by noise in the first vibration amplitude information and the second vibration amplitude information are restrained, the ratio of the vibration amplitude information to the speckle information is improved, and the accuracy of the vibration amplitude information is improved.

According to the embodiments of the present disclosure, the laser vibration meter 100 may perform photoelectric conversion on the first interference light and the second interference light to obtain a first interference electric signal and a second interference electric signal corresponding to the first interference light and the second interference light, and may obtain amplitude information of the first interference electric signal and the second interference electric signal through the first interference electric signal and the second interference electric signal, where the amplitude information may represent vibration amplitude information of the measured object. According to an embodiment of the present disclosure, in the case of actual vibration measurement, it may be assumed that the noise is white noise, i.e., the speckle information may be generated as affected by the white noise. The first interference light in the case of actual vibration measurement can be expressed by the following formula (1).

Wherein f1 (t) is carrier modulation information of the first interference light under the actual vibration measurement condition; a1 (t) is amplitude information corresponding to the first interference light under the actual vibration measurement condition; w is heterodyne frequency; λ1 is the wavelength of the first interference light under the actual vibration measurement condition; s1 (t) is vibration amplitude information of the measured object corresponding to the first interference light under the actual vibration measurement condition; b is the noise coefficient under the actual vibration measurement condition, and rand (t) is the noise information under the actual vibration measurement condition.

According to an embodiment of the present disclosure, the second interference light in the case of actual vibration measurement can be expressed by the following formula (2).

Wherein f2 (t) is carrier modulation information of the second interference light under the actual vibration measurement condition; a2 (t) is amplitude information corresponding to the second interference light under the actual vibration measurement condition; λ2 is the wavelength of the second interference light under the actual vibration measurement condition; s2 (t) is vibration amplitude information of the object to be measured corresponding to the second interference light in the actual vibration measurement.

According to the embodiment of the disclosure, according to the frequency information of the first interference light under the actual vibration measurement condition, the first vibration amplitude information of the measured object corresponding to the first interference light under the actual vibration measurement condition can be obtained through the quadrature demodulation algorithm, and can be represented by the following formula (3).

Wherein s (t) is the vibration amplitude information of the measured object corresponding to the first interference light under the actual vibration measurement condition and the vibration amplitude information of the measured object corresponding to the second interference light under the actual vibration measurement condition,for the first speckle information, s01 is an arbitrary fixed value since the vibration meter measures relative vibrations.

According to the embodiment of the disclosure, according to the frequency information of the second interference light under the actual vibration measurement condition, the second vibration amplitude information of the measured object corresponding to the second interference light under the actual vibration measurement condition can be obtained through the quadrature demodulation algorithm, and can be represented by the following formula (4).

Wherein,for the second speckle information, s02 is an arbitrary fixed value, since the vibration meter measures relative vibrations.

According to the embodiments of the present disclosure, first vibration amplitude information including first speckle information may be obtained from carrier modulation information of first interference light, and second vibration amplitude information including second speckle information may be obtained from carrier modulation information of second interference light. And combining the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light to obtain the vibration amplitude information of the measured object, so as to inhibit the interference of speckles on the vibration amplitude information of the measured object.

According to the embodiment of the disclosure, the vibration amplitude information of the measured object corresponding to the first interference light under the actual vibration measurement condition and the vibration amplitude information of the measured object corresponding to the second interference light under the actual vibration measurement condition are differentiated (Diff) and then weighted and superimposed and integrated (Int), so that the differentiation purpose can remove the interference of s01 and s02, the noise information can be suppressed, and the specific operation can be represented by the following formula (5):

wherein s3 (t) is vibration amplitude information of the measured object after noise suppression; c1 is a first suppression coefficient; c2 is the second suppression coefficient.

According to an embodiment of the present disclosure, c1 and c2 satisfy c1+c2=1; the specific values of c1 and c2 can be based onAnd->The specific value of (c) is determined, and the suppression of rand (t) is realized through superposition of products of the c1 and the c2, namely, the suppression of noise information is realized.

It is to be understood that the features recited in the various embodiments of the present application and/or in the claims may be combined in various combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the present application. In particular, the features recited in the various embodiments and/or the claims of the present application may be combined and/or combined in various ways without departing from the spirit and teachings of the present application. All such combinations and/or combinations fall within the scope of the present application.

In the description of the present specification, a description referring to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The embodiments of the present application are described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present application. Although the embodiments are described above separately, this does not mean that the measures in the embodiments cannot be used advantageously in combination. The scope of the application is defined by the appended claims and equivalents thereof. Various substitutions and modifications may be made without departing from the scope of the present application, and these substitutions and modifications are intended to fall within the scope of the present application.

Claims

1. A multi-wavelength based laser vibrometer comprising:

A laser configured to generate laser light, wherein the laser light comprises a first wavelength laser light and a second wavelength laser light;

a transmitter configured to transmit the first detection light and the second detection light to a measured object, and to receive a first reflected light obtained by reflecting the first detection light by the measured object and a second reflected light obtained by reflecting the second detection light by the measured object; and

and the processor is configured to obtain first interference light according to the first reference light and the first reflected light, obtain second interference light according to the second reference light and the second reflected light, and obtain vibration amplitude information of the measured object according to the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light.

2. The laser vibrometer of claim 1, wherein the transmitter comprises:

receiving the first probe light and the second probe light via the first end;

the first detection light and the second detection light are sent to the tested object through the second end;

receiving first reflected light obtained by reflecting the first detection light by the tested object and second reflected light obtained by reflecting the second detection light by the tested object through the second end; and

the first reflected light and the second reflected light are sent to the processor via the third end.

3. The laser vibrometer of claim 1, wherein the transmitter comprises:

receiving the first probe light and the second probe light via the fourth end;

transmitting the first polarized detection light and the second polarized detection light to the tested object through the fifth end under the condition that the first polarized spectroscope reflects the first polarized detection light and the second polarized detection light, wherein the first polarized detection light is reflected by the tested object to obtain first reflected light, the second polarized detection light is reflected by the tested object to obtain second reflected light, and the first reflected light and the second reflected light are received through the fifth end; and

and transmitting the first reflected light and the second reflected light to the processor through the sixth end under the condition that the first polarization beam splitter transmits the first reflected light and the second reflected light.

4. The laser vibrometer of claim 1, wherein the transmitter comprises:

a second point diffractive fiber optic circulator including a seventh end, an eighth end, a ninth end, a prism group configured to:

receiving the first detection light and the second detection light through the seventh end;

Changing the polarization states of the first detection light and the second detection light through the prism group, and transmitting the first detection light and the second detection light with the changed polarization states to the eighth end;

transmitting first detection light and second detection light changing the polarization state to the tested object through the eighth end, and receiving the first reflected light and the second reflected light through the eighth end; the first reflected light and the second reflected light are transmitted to the ninth end through the prism group; and

and sending the first reflected light and the second reflected light to the processor via the ninth end.

5. The laser vibration meter of claim 4, wherein the prism set comprises:

a parallelogram prism configured to receive the first detection light and the second detection light via a first side of the parallelogram prism, wherein the polarization states of the first detection light and the second detection light are adjusted at the first side to obtain third polarized detection light and fourth polarized detection light;

the side face of the triangular prism, where the longest side of the triangular prism is connected with the second side face of which the included angle is an acute angle, a reflecting film structure is arranged between the contact faces of the triangular prism and the parallelogram prism, and the reflecting film structure is configured to reflect the third polarized detection light and the fourth polarized detection light; the side surface of the trapezoid prism, where the trapezoid edge of the trapezoid prism is located, is connected with a third side surface, where an included angle of the first side surface is an obtuse angle, a semi-transparent and semi-reflective film structure is arranged between contact surfaces of the trapezoid prism and the parallelogram prism, and the semi-transparent and semi-reflective structure is configured to reflect the third polarized detection light and the fourth polarized detection light;

The trapezoidal prism is further configured to transmit the first reflected light and the second reflected light to the ninth end.

6. The laser vibrometer of claim 1, wherein the transmitter comprises:

transmitting the first circular deflection detection light and the second circular deflection detection light to the tested object through the tenth end, and receiving first reflected light obtained by reflecting the first circular deflection detection light by the tested object and second reflected light obtained by reflecting the second circular deflection detection light by the tested object through the tenth end;

under the condition that the tenth end receives the first reflected light and the second reflected light, the polarization states of the first reflected light and the second reflected light are adjusted through the 1/4 wave plate, and first polarized reflected light and second polarized reflected light are obtained;

Transmitting the first polarized reflected light and the second polarized reflected light to the twelfth end via the second polarizing beamsplitter; and

7. The laser vibration meter according to any one of claims 1-6, wherein the processor is further configured to:

calculating first vibration amplitude information including first speckle information according to the frequency information of the first interference light, and calculating second vibration amplitude information including second speckle information according to the frequency information of the second interference light;

and carrying out weighted superposition on the differential result of the first vibration amplitude information and the differential result of the second vibration amplitude information, and integrating the weighted superposition calculation result to obtain the vibration amplitude information for inhibiting the first speckle information and the second speckle information.

8. A laser vibrometer according to any one of claims 1 to 3 further comprising:

the lens is arranged between the transmitter and the measured object and is configured to collect the first detection light and the second detection light, collect the first reflection light of the first detection light and collect the second reflection light.

9. A multi-wavelength based laser vibration measurement method, comprising:

the processor obtains first interference light according to the first reference light and the first reflected light, obtains second interference light according to the second reference light and the second reflected light, and obtains vibration amplitude information of the measured object according to the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light.

10. The method of claim 9, wherein the combining the first vibration amplitude information of the measured object corresponding to the first interference light and the second vibration amplitude information of the measured object corresponding to the second interference light to obtain the vibration amplitude information of the measured object includes: