CN104898284A - Aspheric extender lens - Google Patents

Abstract

The invention relates to an aspheric extender lens. The aspheric extender lens is a solid lens formed by enclosing an aspheric surface and a cylindrical side surface, the aspheric surface is an ellipsoid, and when the ellipsoid is vertically arranged, the following equation is met: x<2>/9+y<2>/18+z<2>/9=1. The extender lens provided by the invention can obtain elliptical light spots and realize asymmetric illumination. The extender lens has good universality for light beams with different wavelengths, and when performing speckle measuring on asymmetric objects, can effectively reduce the light loss and improve the light brightness.

Description

A kind of aspheric surface beam expanding lens

Technical field

The present invention relates to optical lens, be specifically related to a kind of aspheric surface beam expanding lens.

Background technology

Beam expanding lens has increase width of light beam, strengthens clear field, is convenient to the advantages such as observation and measurement, is widely used in the optical systems such as laser alignment, electronic speckle pattern interferometry, Fresnel holography or experiment.Sphere beam expanding lens is because its technological requirement is low, it is simple to process, and the advantage application such as easy realization are general, also substantially meet the requirement of testing with scientific research.Along with the development of Electronic speckle pattern interferometry and digital hologram detection technique, the requirement that laser forms corrugated quality through beam expanding lens improves further, particularly to the measurement of irregularly shaped object or in big shearing electronic speckle three-dimensional measurement, need asymmetric lighting, therefore traditional sphere beam expanding lens cannot meet picture element and asymmetrical requirement.Compared to spherical mirror, aspheric mirror has the advantage of low spherical aberration, can improve the quality of light wave, and thus many precision measurements, scientific research are carried out based on the production of aspheric mirror and exploitation.

Summary of the invention

For problems of the prior art, the invention provides a kind of aspheric surface beam expanding lens.

In order to solve above technical matters, technical scheme of the present invention is:

A kind of aspheric surface beam expanding lens, be the solid lens surrounded by aspheric surface and column side, described aspheric surface is ellipsoid, and when described ellipsoid is for vertically placing, satisfied equation is:

Preferably, described aspheric surface beam expanding lens is made up of BK7 glass.

Preferably, described aspheric summit is 3mm along the radius-of-curvature of x-axis.

Preferably, described aspheric summit is 6mm along the radius-of-curvature of y-axis.

Preferably, directional light can expand and be shaped as oval hot spot by described aspheric surface beam expanding lens.

The application of described aspheric surface beam expanding lens in three-dimensional electronic speckle interferometer asymmetric lighting.

Advantageous Effects of the present invention is:

1, beam expanding lens of the present invention can obtain oval hot spot, can realize asymmetric lighting.

2, the light beam of beam expanding lens of the present invention to different wave length has good universality.

3, beam expanding lens of the present invention is when carrying out speckle measurement to asymmetric objects, effectively can reduce light and scatter and disappear, improve luminance brightness.

Accompanying drawing explanation

Fig. 1 is main TV structure schematic diagram of the present invention;

Fig. 2 is vertical view of the present invention;

Fig. 3 is the light refraction face in the non-paraxial situation of lens;

Fig. 4 is the light refraction face in the paraxial situation of lens;

Fig. 5 is the schematic diagram of vertical ellipsoid in coordinate axis;

Fig. 6 is the oval schematic diagram in yoz plane;

Fig. 7 be after parallel beam that analog computation draws is expanded by aspheric surface on 800mm place viewing plane disperse image.

Wherein, 1, aspheric surface, 2, side.

Embodiment

Below in conjunction with accompanying drawing, the present invention is further illustrated.

As depicted in figs. 1 and 2, a kind of aspheric surface beam expanding lens, be the solid lens surrounded by aspheric surface 1 and column side 2, described aspheric surface 1 is ellipsoid.

Described aspheric surface beam expanding lens is made up of BK7 glass (also known as K9 glass, refractive index n=1.51680).

Lens employing semi-major axis 2mm, semi-minor axis 1.5mm, thickness are the BK7 glass of 2mm.In order to obtain perpendicular ellipsoid as shown in Figure 5 and Figure 6, utilize the revolving property of Biconic face type, design D place, summit radius-of-curvature is along the x-axis direction 3mm, i.e. c=3mm, and in yoz plane, oval conic value is 1, with seasonal a=3mm.So summit is along y-axis radius of curvature R ₀=a (1+k)=6mm; The intercept of ellipsoid y-axis the surface equation that the ellipsoid then designed meets is lens sizes is substituted into surface equation can obtain, the maximum gauge of x-axis direction curved surface is about 0.354mm, and the maximum gauge of y-axis direction curved surface is about 0.41mm.

The ultimate principle of beam expanding lens design

Different optical systems is different to the converging power of light beam.In physics, the converging power of optical system to light beam is called as focal power.Focal power equals the difference of image space light beam convergence and object space light beam convergence, conventional letter represent.The focal power of plane of refraction wherein n' is image space refractive index, and n is object space refractive index, and R is spherical radius, and f' is image space focal length, and f is object space focal length.Above-mentioned focal power equation is all pervasive to any optical system.Under near-axial condition, the deviation ability of focal power to light meets paraxial rays ray tracing equations (PRTE).Consider the light refraction face in non-as shown in Figure 3 paraxial situation.There is a light to incide plane of refraction with height y in figure, and reflect.In the point of intersection of light and plane of refraction, depict the normal in face and the straight line parallel with optical axis, they are all represented by dotted lines.The angle between light and optical axis (U and U'), the incident angle of light and the curvature C (C=1/R) of refraction angle (I and I') and plane of refraction has also been marked in figure.If intersection point moves down close to optical axis, Fig. 3 just will develop into paraxial situation as shown in Figure 4.

According to mathematical relation, in the diagram ,-α=y/R, then angle [alpha] can be expressed as

α＝-y/R＝-y C (1)

Pass between each angle in Fig. 4 is

$\left\{\begin{array}{c}i=-\mathrm{\&alpha;}+u\\ i=-\mathrm{\&alpha;}+u^{\&prime;}\end{array}\right.---\left(2\right)$

And Si Nieer formula is expressed as under near-axial condition

ni＝n'i' (3)

Formula (2) is substituted into formula (3) have

n(-α+u)＝n'(-α+u')

n'u'＝nu-nα+n'α

n′u′＝nu+(n′-n)α (4)

Formula (1) is substituted into formula (4) obtain

n′u′＝nu-y[(n′-n)C] (5)

Formula (5) is called bending paraxial rays ray tracing equations (PRTE), wherein, it is the focal power of single plane of refraction.From formula (5), numerical value larger, deflection of light ability is stronger.Therefore, the radius-of-curvature changing plane of refraction can change the deviation direction of light, can realize the shaping to circular light spot thus.

As shown in Figure 7, software simulation result shows: novel beam expanding lens can realize aspheric surface, non-homogeneously to expand, the directional light of diameter 2mm, wavelength 632.8nm can be made at 800mm place to expand the oval hot spot being shaped as 280mm × 140mm, and to the light beam of different wave length, there is good universality.

By reference to the accompanying drawings the specific embodiment of the present invention is described although above-mentioned; but the restriction not to invention protection domain; one of ordinary skill in the art should be understood that; on the basis of technical scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still in protection scope of the present invention.

Claims (6)

1. an aspheric surface beam expanding lens, is characterized in that: described aspheric surface beam expanding lens is the solid lens surrounded by aspheric surface and column side, and described aspheric surface is ellipsoid, and when described ellipsoid is for vertically placing, satisfied equation is:

2. according to the aspheric surface beam expanding lens in claim 1, it is characterized in that: described aspheric surface beam expanding lens is made up of BK7 glass.

3. according to the aspheric surface beam expanding lens in claim 2, it is characterized in that: described aspheric summit is 3mm along the radius-of-curvature of x-axis.

4. according to the aspheric surface beam expanding lens in claim 3, it is characterized in that: described aspheric summit is 6mm along the radius-of-curvature of y-axis.

5., according to the arbitrary described aspheric surface beam expanding lens of claim 4, it is characterized in that: directional light can expand and be shaped as oval hot spot by described aspheric surface beam expanding lens.

6. according to the application of the arbitrary described aspheric surface beam expanding lens of claim 1-5 in three-dimensional electronic speckle interferometer asymmetric lighting.