CN116224611A - Arbitrary time waveform light pulse generating device - Google Patents

Arbitrary time waveform light pulse generating device Download PDF

Info

Publication number
CN116224611A
CN116224611A CN202310020593.7A CN202310020593A CN116224611A CN 116224611 A CN116224611 A CN 116224611A CN 202310020593 A CN202310020593 A CN 202310020593A CN 116224611 A CN116224611 A CN 116224611A
Authority
CN
China
Prior art keywords
light
grating
imaging system
short pulse
pulse
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310020593.7A
Other languages
Chinese (zh)
Inventor
黄大杰
范薇
李国扬
杜彤耀
程贺
李学春
朱健强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Institute of Optics and Fine Mechanics of CAS
Original Assignee
Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Institute of Optics and Fine Mechanics of CAS filed Critical Shanghai Institute of Optics and Fine Mechanics of CAS
Priority to CN202310020593.7A priority Critical patent/CN116224611A/en
Publication of CN116224611A publication Critical patent/CN116224611A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
    • G02B27/4233—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive element [DOE] contributing to a non-imaging application
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
    • G02B27/0938—Using specific optical elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
    • H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

An arbitrary time waveform light pulse generating device comprises a short pulse light source, a light splitting element, a collimation and beam expansion system, a first imaging system, a grating, a second imaging system, a space shaping element, a coupling lens and a single-mode optical fiber; after passing through the light splitting element, the short pulse light is used as a short pulse seed source, the transmitted light is collimated and expanded to fully irradiate the effective light passing area of the grating, and the reflected light pulse phase wavefront has inclination with a certain angle compared with the intensity wavefront. When the space shaping element is combined with the rear coupling system to form preset space transmittance distribution, the phase wavefront of the light pulse is also modulated by the corresponding space transmittance, and after the influence of space-time distortion and the like is eliminated by the rear coupling system, the coupled-out light pulse time waveform has a linear corresponding relation with the preset space transmittance distribution, and the coupled-out light pulse time waveform and the short pulse light reflected by the light splitting element belong to a homologous relation. The invention not only realizes absolute homology of long and short pulses, but also has the advantages of high time resolution, wide time width range, simple optical structure, no dependence on electronic chips and the like.

Description

Arbitrary time waveform light pulse generating device
Technical Field
The invention relates to the technical field of time waveform control of optical pulses, in particular to an arbitrary time waveform optical pulse generating device.
Background
In the field of inertial fusion, the interaction process of laser and substances can be precisely controlled by precisely regulating and controlling the laser time waveform converged on a target pill, so that the fusion process and fusion efficiency are directly affected. Therefore, the research on the precise control technology of the laser pulse time waveform has important significance for improving the inertia fusion efficiency.
For precise regulation and control of laser time pulse, there are two main requirements: on one hand, multiple paths of optical pulses need to be precisely synchronized to achieve synchronization to reach a target pill, and absolute zero synchronization is difficult to achieve when long and short optical pulses of different paths are non-homologous; on the other hand, the temporal waveform of the light pulse of each path needs to be precisely adjustable, and the resolution needs to be better than more than one percent of the total width of the time. Although any shaped optical pulse with a time width of several nanoseconds can be generated by combining the electric pulse AWG technology with the electro-optical modulator, when the required time width of the optical pulse is about hundred picoseconds, the time resolution requirement reaches the picosecond order, and is limited by the bandwidth of an electronic element, and the electronic method cannot generate any shaped optical pulse with such high time resolution.
Although time resolution accuracy can be improved by optical techniques such as time-frequency conversion, there are problems that an optical path is complicated and a time width is difficult to extend.
Disclosure of Invention
The invention aims to solve the problems that zero synchronization precision cannot be realized, pulse time resolution cannot reach picosecond level and the like in the conventional arbitrary light pulse generation technology, and provides an arbitrary time waveform light pulse generation device. When the space shaping element is combined with the rear coupling system to form preset space transmittance distribution, the phase wavefront of the light pulse is also modulated by the corresponding space transmittance, and after the influence of space-time distortion and the like is eliminated by the rear coupling system, the coupled light pulse time waveform and the preset space transmittance distribution have a linear corresponding relation. Therefore, by designing proper optical system parameters and transmittance distribution of the space shaping element, the device can output light pulses with preset time waveforms, and the light pulses belong to a homologous relationship with the short pulse light reflected by the light splitting element, so that absolute homology of long and short pulses is realized. Compared with the existing arbitrary light pulse generation technology, the light pulse generation device has the advantages of high synchronization precision, high time resolution, wide time width range (hundred picoseconds to nanosecond magnitude), simple optical structure, no dependence on an electronic chip and the like.
The technical scheme of the invention is as follows:
an arbitrary time waveform light pulse generating device comprises a short pulse light source and is characterized in that: the system also comprises a light splitting element, a collimation and beam expansion system, a first imaging system, a grating, a second imaging system, a space shaping element, a coupling lens and a single-mode optical fiber which are sequentially arranged along the transmission direction of the short pulse light source;
the short pulse light outputted by the short pulse light source passes through the light splitting element, the reflected light is used as a short pulse seed source, and the transmitted light sequentially passes through the collimation and beam expansion system and the first imaging system and then enters the light splitting element at an incident angle theta g Irradiating the effective light-transmitting area of the grating to make the diffraction reflected by the gratingThe phase wavefront and the intensity wavefront of the light pulse are inclined, and the diffracted light passes through the second imaging system and then enters the optical imaging system at an incident angle theta SLM And irradiating the space shaping element to enable the space shaping element and the grating to form an accurate object and image relationship, and loading transmittance or phase distribution on the space shaping element to enable the distribution of the light spot coverage area in the modulation dimension to have a linear corresponding relationship with the spatial transmittance distribution.
Further, the time width t of the short pulse light source in Approaching the short pulse limit of the fourier transform.
Further, the short pulse light outputted by the short pulse light source sequentially passes through the light splitting element, the collimation and beam expansion system and the first imaging system and then irradiates the grating with a certain incident angle, and the incident angle satisfies a grating equation.
Further, the short pulse light outputted by the short pulse light source sequentially passes through the light splitting element, the collimation and beam expansion system and the first imaging system, and irradiates on the grating with a certain incident angle and a certain light spot size, and the light spot size is as close as possible to the effective light transmission area of the grating.
Further, the short pulse light outputted by the short pulse light source sequentially passes through the light splitting element, the collimation and beam expansion system, the first imaging system, the grating and the second imaging system and then irradiates on the space shaping element, and the light spot size is as close as possible to the effective working area of the space shaping element.
Further, the spatial shaping element is inclined at an angle, and the inclination angle of the grating meet the object-image relationship of the second imaging system.
Further, the coupling lens is an aberration-eliminating lens, so that the size of the converging light spot is close to the diffraction limit size.
Further, the numerical aperture of the single-mode fiber is larger than the numerical aperture of the converging light beam of the coupling lens.
Further, an incident angle θ of the spatial shaping element SLM Incidence angle θ with the grating g The following relationships are satisfied: tan (θ) SLM )＝M 2 ·tan(θ g ) Wherein M is 2 Is the magnification of the second imaging system.
Compared with the prior art, the invention has the beneficial effects that:
by utilizing the space-time coupling characteristic of laser pulse and through the design of optical system, the linear correspondence exists between the time waveform of pulse and the space transmittance distribution of the space shaping element, so that not only the high-precision arbitrary shaping of the time waveform of long pulse light is realized, but also the absolute homology of long pulse and short pulse is realized.
By utilizing the characteristic that the phase wavefront and the intensity wavefront of the light pulse reflected by the grating have inclination angles and combining the characteristics of image transmission, space-time coupling of the inclined pulse wavefront and the like, the precise regulation and control of the pulse time waveform is realized by regulating and controlling the transmittance distribution of the space shaping element.
By designing appropriate optical system parameters and transmittance distribution of the spatial shaping element, the device can output laser pulses with preset time waveforms.
Compared with the existing time pulse generation technology, the method has the advantages of high synchronization precision, high time resolution, wide time width range (in the order of hundreds of picoseconds to nanoseconds), simple optical structure, no dependence on an electronic chip and the like.
Drawings
Fig. 1 is a schematic diagram of the structure of an arbitrary time waveform light pulse generating apparatus with zero synchronization accuracy of the present invention.
FIG. 2 is a schematic diagram of a collimation and expansion system according to an embodiment of the invention.
Fig. 3 is a schematic structural diagram of a first imaging system according to an embodiment of the invention.
Fig. 4 is a schematic structural view of a second imaging system in an embodiment of the present invention).
Detailed Description
The invention is further illustrated in the following examples and figures, which should not be taken to limit the scope of the invention.
Referring to fig. 1, fig. 1 is a diagram of an arbitrary method with zero synchronization accuracy according to the present inventionThe schematic structural diagram of the device for generating the light pulse with the intentional time waveform can be seen, and the device for generating the light pulse with the random time waveform comprises a short pulse light source 1, a light splitting element 1a, a collimation and beam expanding system 2, a first imaging system 3, a grating 4, a second imaging system 5, a space shaping element 6, a coupling lens 7 and a single-mode optical fiber 8, wherein the light splitting element 1a, the collimation and beam expanding system 2, the first imaging system 3, the grating 4, the second imaging system 5, the space shaping element 6, the coupling lens 7 and the single-mode optical fiber 8 are sequentially arranged along the transmission direction of the short pulse light source. The short pulse light outputted by the short pulse light source sequentially passes through the light splitting element, the collimation and beam expansion system and the first imaging system and then enters the light splitting element, the collimation and beam expansion system and the first imaging system at an incident angle theta g Irradiating the effective light passing area of the grating to enable the phase wave front and the intensity wave front of the diffracted light pulse reflected by the grating to be inclined, wherein the diffracted light passes through the second imaging system and then enters the second imaging system at an incident angle theta SLM And irradiating the space shaping element to enable the space shaping element and the grating to form an accurate object and image relationship, and loading transmittance or phase distribution on the space shaping element to enable the distribution of the light spot coverage area in the modulation dimension to have a linear corresponding relationship with the spatial transmittance distribution.
The short pulse light source 1 may be a solid state or fiber laser with output pulse time of femtosecond, picosecond or nanosecond width. The beam splitting element 1a in this embodiment is typically a beam splitting cube, and the reflection/transmission ratio is set according to the energy requirement of the subsequent optical path. The collimation and beam expansion system 2 consists of a pair of concave lenses and convex lenses, wherein the virtual focus of each concave lens and the real focus of each convex lens are overlapped at a position F, the focal lengths of the two are F1 and F2 respectively, and the beam expansion ratio=f2/F1 of the system is shown in fig. 2. The first imaging system 3 is an imaging transmission structure formed by a pair of convex lenses, the focal length of the two lenses is f3 and f4 respectively, and the two lenses are separated by f3+f4 so as to ensure that the back focus of the front lens and the front focus of the rear lens are mutually overlapped, and the magnification=f4/f 3 of the imaging system is shown in fig. 3. The grating 4 is a reflective grating, and the reflective film layer material can be an aluminum film, a gold film, a dielectric film material or the like. The second imaging system 5 is an imaging transmission structure formed by a pair of convex lenses, the focal length of the two lenses is f5 and f6 respectively, and the two lenses are separated by f5+f6 to ensure that the back focus of the front lens and the front focus of the rear lens coincide with each other, and the magnification=f6/f 5 of the imaging system is shown in fig. 4. The spatial shaping element 6 may be a transmissive amplitude-type spatial light modulator, a transmissive phase-type spatial light modulator, a reflective amplitude-type spatial light modulator or a reflective phase-type spatial light modulator, the applicable wavelength being matched to the wavelength of the incident light. The coupling lens 7 is a cemented aberration-eliminating lens or an aspherical lens, and the applicable wavelength is matched with the wavelength of incident light. The single mode fiber 8 is a single mode fiber with no inclination angle on the end face, the size of the inner hole of the fiber is larger than or equal to the size of a light spot converged by the coupling lens, and the numerical aperture of the fiber is larger than or equal to the numerical aperture of the converging light beam of the coupling lens.
The operation method of the invention comprises the following steps:
the output light wavelength of the short pulse light source is recorded as lambda, and the beam waist radius is recorded as w 0 Time width τ 0 The beam expansion multiplying power of the collimation and beam expansion system is M 0 The magnification of the first imaging system is M 1， The magnification of the second imaging system is M 2 The grating density is lambda, and the diffraction angle after being reflected by the grating is theta. The design and adjustment are carried out according to the following steps:
(1) When the output pulse time width is required to be 2τ and the pulse intensity distribution is I (t) with time (t is less than or equal to 2τ), the relation is required to be satisfied: τ=w 0 ·M 0 ·M 1 λ/(c·Λ·cos (θ), M is configured according to this formula 0 、M 1 、M 2 Parameters, Λ, and θ, where c=3×10 8 m/s。
(2) Adjusting the angle of the space shaping element to make the space shaping element and the grating mutually form an object and an image relationship, and the incidence angle theta of the space shaping element SLM Incidence angle θ with the grating g The following relationships are satisfied: tan (θ) SLM )＝M 2 ·tan(θ g )。
(3) And adjusting the transmittance or phase distribution loaded on the space shaping element to enable the distribution of the light spot coverage area in the modulation dimension to be in a linear corresponding relation with the I (t) distribution.
(4) And precisely fine-tuning each dimension of the single-mode fiber such as up and down, left and right, inclination angle and the like to enable the output waveform to be close to a preset state.
Example 1:
the short pulse light source 1 outputs lightA wavelength of 1053nm and a beam waist radius of w 0 Time width τ =2 mm 0 The beam expansion multiplying power of the collimation and beam expansion system 2 is less than or equal to 1ps and is M 0 =3.5, the magnification of the first imaging system 3 is M 1 ＝7 ， The magnification of the second imaging system 5 is M 2 The density of the grating 4 is Λ=1800 l/mm, and the diffraction angle after the grating reflection is θ=71.4 degrees. As can be seen, the device outputs pulses with a time width 2τ=970 ps.
The focal length of the concave lens in the collimation and beam expansion system 2 is minus 10mm, and the focal length of the convex lens is 35mm.
The focal lengths of the two lenses in the first imaging system 3 are taken to be 50mm and 350mm, respectively.
The grating 4 adopts a reflective gold film grating, the linear density Λ=1800 l/mm, and the effective area is more than or equal to 100mm×100mm.
The focal lengths of the two lenses in the second imaging system 5 are taken to be 40mm and 210mm, respectively.
The spatial shaping element 6 is an amplitude LCOS type spatial light modulator, such as an HDSLM80RA from rayleigh, with a resolution of 1920 x 1200 and a unit pixel size of 8 microns. The transmittance distribution loaded on the device has a linear corresponding relation with the time intensity distribution of the pulse in the one-dimensional direction of the reflection normal.
The coupling lens has a focal length of 10cm and a single-mode fiber core diameter of 10um.
Example 2
The variation from embodiment 1 is that the short pulse light source 1 has a beam waist radius w 0 Time width τ =10mm 0 Less than or equal to 50ps, the magnification of the second imaging system 5 is M 2 =4/105, the effective area of the grating 4 must meet ≡500mm×500mm when the other optical system or element parameters are unchanged. The space shaping element 6 still adopts the same device model as in embodiment 1.
In this condition, the time width of the output pulse of the device reaches 2τ=4.85 ns.
The transmittance distribution applied to the spatial shaping element 6 is such that when the one-dimensional direction of the reflection normal line and the temporal intensity distribution of the pulse are in a linear correspondence, the device outputs a desired optical pulse having a specific temporal waveform.

Claims (9)

1. An arbitrary time waveform light pulse generating device, includes the short pulse light source, its characterized in that: the system also comprises a light splitting element, a collimation and beam expansion system, a first imaging system, a grating, a second imaging system, a space shaping element, a coupling lens and a single-mode optical fiber which are sequentially arranged along the transmission direction of the short pulse light source;
the short pulse light outputted by the short pulse light source passes through the light splitting element, the reflected light is used as a short pulse seed source, and the transmitted light sequentially passes through the collimation and beam expansion system and the first imaging system and then enters the light splitting element at an incident angle theta g Irradiating the effective light passing area of the grating to enable the phase wave front and the intensity wave front of the diffracted light pulse reflected by the grating to be inclined, wherein the diffracted light passes through the second imaging system and then enters the second imaging system at an incident angle theta SLM And irradiating the space shaping element to enable the space shaping element and the grating to form an accurate object and image relationship, and loading transmittance or phase distribution on the space shaping element to enable the distribution of the light spot coverage area in the modulation dimension to have a linear corresponding relationship with the spatial transmittance distribution.
2. The arbitrary time waveform light pulse generating apparatus as defined in claim 1, wherein: time width t of the short pulse light source in Approaching the short pulse limit of the fourier transform.
3. The arbitrary time waveform light pulse generating apparatus as defined in claim 1, wherein: the short pulse light output by the short pulse light source sequentially passes through the light splitting element, the collimation and beam expansion system and the first imaging system and then irradiates the grating with a certain incident angle, and the incident angle meets the grating equation.
4. An arbitrary time waveform light pulse generating apparatus as defined in claim 1 or 3, wherein: the short pulse light output by the short pulse light source sequentially passes through the light splitting element, the collimation and beam expansion system and the first imaging system and then irradiates the grating with a certain incidence angle and a certain light spot size, wherein the light spot size is as close as possible to the effective light transmission area of the grating.
5. The arbitrary time waveform light pulse generating apparatus as defined in claim 1, wherein: the short pulse light output by the short pulse light source sequentially passes through the light splitting element, the collimation and beam expansion system, the first imaging system, the grating and the second imaging system and then irradiates on the space shaping element, and the light spot size is as close as possible to the effective working area of the space shaping element.
6. The arbitrary time waveform light pulse generating apparatus as defined in claim 1, wherein: the space shaping element is inclined at a certain angle, and the inclination angle of the grating meet the object-image relationship of the second imaging system.
7. The arbitrary time waveform light pulse generating apparatus as defined in claim 1, wherein: the coupling lens is an aberration-eliminating lens, so that the size of the converging light spots is close to the diffraction limit size.
8. The arbitrary time waveform light pulse generating apparatus as defined in claim 1, wherein: the numerical aperture of the single-mode optical fiber is larger than that of the converging light beam of the coupling lens.
9. An arbitrary time waveform light pulse generating apparatus as defined in any one of claims 1-8, wherein: incidence angle θ of the spatial shaping element SLM Incidence angle θ with the grating g The following relationships are satisfied: tan (θ) SLM )＝M 2 ·tan(θ g ) Wherein M is 2 Is the magnification of the second imaging system.
CN202310020593.7A 2023-01-06 2023-01-06 Arbitrary time waveform light pulse generating device Pending CN116224611A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310020593.7A CN116224611A (en) 2023-01-06 2023-01-06 Arbitrary time waveform light pulse generating device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310020593.7A CN116224611A (en) 2023-01-06 2023-01-06 Arbitrary time waveform light pulse generating device

Publications (1)

Publication Number Publication Date
CN116224611A true CN116224611A (en) 2023-06-06

Family

ID=86588404

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310020593.7A Pending CN116224611A (en) 2023-01-06 2023-01-06 Arbitrary time waveform light pulse generating device

Country Status (1)

Country Link
CN (1) CN116224611A (en)

Similar Documents

Publication Publication Date Title
CN111458776B (en) Method and device for preparing femtosecond optical fiber interference direct-writing chirped grating
JP4716663B2 (en) Laser processing apparatus, laser processing method, and structure manufactured by the processing apparatus or processing method
US7072566B2 (en) Ultrashort-pulse laser-working method and apparatus and structural bodies produced by using the same
CN105445943B (en) A kind of generation device and production method of fractional order perfection vortex beams
US11982945B2 (en) Two-photon-polymerization laser direct writing system based on acousto-optic deflector
CN106964893B (en) Laser pre-treated device and processing method for optical element
US11134231B2 (en) Light control device
CN104765099A (en) Device and method for inscribing fiber period adjustable fiber grating
CN112327397A (en) Method for manufacturing large-area volume grating by femtosecond plasma grating direct writing
US10101634B2 (en) Adjustable speed fast laser scanning system and two-photon microscope associated
CN114279558B (en) Complex amplitude measuring device and method based on modulation type double detectors
CN110587118A (en) Double-laser beam combining device and double-laser composite processing light beam system
CN101303447A (en) Laser converging device with variable incidence angle
CN116224611A (en) Arbitrary time waveform light pulse generating device
CN1182411C (en) Preparation of grating device by utilizing ultrashort laser pulse and method for implementing holographic storage
CN110119071B (en) Interference lithography system, printing device and interference lithography method
CN101339300B (en) Double light beam interference adjustable gain laser writing filtering method and apparatus
CN210703082U (en) Double-laser beam combining device and double-laser composite processing beam system
KR101667792B1 (en) Optical apparatus using interference beam
CN113960891A (en) Method and device for parallel interpenetration super-resolution high-speed laser direct writing photoetching
CN201278063Y (en) Light intensity distribution regulating apparatus for focal point zone
CN114280800B (en) Space-time shaping device, space-time shaping system and method
CN206981987U (en) Laser pre-treated device for optical element
CN219801482U (en) Three-frequency laser rapid output device
CN118068466B (en) Surface plasmon bottle preparation method and device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination