CN103322942A - Facial form detection method of each optical element of optical system based on wave aberration - Google Patents

Abstract

The invention discloses a facial form detection method of each optical element of an optical system based on wave aberration. The facial form detection method of each optical element of an optical system based on wave aberration comprises the following steps of: S1, adjusting each element of the optical system roughly, so that the wave aberration of the optical system can be detected effectively by a wave aberration detection device; S2, adjusting the space position of each optical element, measuring the wave aberration of the optical system under each position state, and recording; and S3, inputting the recorded position states of the optical elements as well as the wave aberration of the corresponding optical system into a processor, and calculating the facial form of each optical element. According to the invention, the facial form of each optical element in the optical system is determined through detecting the wave aberration of the optical system; at an assembling stage, facial data of each optical element of the optical system is obtained through the finally measured wave aberration of the optical system; the facial form detection method of each optical element of an optical system based on wave aberration can be used for eliminating the system wave aberration caused by facial form errors, is suitable for an optical system the facial form data of which cannot be measured accurately, prevents misoperation caused by facial form data detection errors during a subsequent adjustment process, and improves the imaging quality of the optical system.

Description

Detection method based on each optical element face shape of optical system of wave aberration

Technical field

The invention belongs to the optical engineering field, relate to each optical element surface testing method of a kind of optical system, relate in particular to a kind of detection method of each the optical element face shape of optical system based on wave aberration.

Background technology

The picture element of optical system depends primarily on optical design, optical material, the quality of optics processing and optical alignment.The error suseptibility of optical design, the error of the kind of residual aberration and magnitude and optical material characteristic directly affects the final picture element of optical system.When optical design and optical material were specific, the factor that affects picture element mainly came from optics processing and optical alignment process.The error in optics processing and dress school mainly is owing to being subjected to the restriction of technological level, the deviations such as the optical element radius-of-curvature that causes, thickness, off-centre and element surface shape.The error that all these processing, assembling bring shows as decrease resolution to the combined influence of optical system picture element, and distortion increases, and the disc of confusion of picture point increases, transport function reduction etc.At this moment, by the fine setting to the relative space position of each optical element, can compensate because processing or debug the aberration that error causes improves the image quality after real system is debug.Wherein, to optical element carry out translation and tilt can the compensating optical element radius-of-curvature, the aberration that causes of thickness and eccentric error, optical element is rotated the aberration that can the compensating optical element face shape error causes.

The aberration that the optical component surface shape error is caused mainly relies on the lens face shape deflection data of debuging front measurement when compensating, yet debuging in the process of reality, the lens face shape deflection data can not be measured sometimes exactly, especially for Large Aperture Lenses, the restriction of examined condition can only measure the partial face shape of lens sometimes, in addition, Large Aperture Lenses after debuging, mechanical support, stress deformation and environmental change also can make lens surface deform.If the aberration that still utilizes the surface shape measurement data debug front measurement to come the offset lens face shape error to cause can bring very large error to calculating, even the result of calculation that can make the mistake, cause follow-up improper operation of debuging in the process.

Summary of the invention

In order to solve the technical matters that exists in the prior art, the objective of the invention is to propose a kind of detection method of each the optical element face shape of optical system based on wave aberration, can be at last assembling stage, directly by the final optical system wavefront aberration of measuring, obtain the face graphic data of each optical element of optical system.

Technical solution of the present invention is: the invention provides a kind of detection method of each the optical element face shape of optical system based on wave aberration, each optical element face shape detecting step of described optical system is as follows:

Step S1: each optical element of optical system is slightly debug, optical system wavefront aberration can effectively be detected by the wave aberration pick-up unit;

Step S2: the locus to each optical element is adjusted, and measures the wave aberration of optical system under each location status, simultaneously the location status of recording optically element and the optical system wavefront aberration under this state;

Step S3: with corresponding optical system wavefront aberration input processor under the position of optical element state of record and this state, calculate the face shape of each optical element.

Beneficial effect of the present invention: each optical element surface testing method of optical system based on wave aberration that the present invention proposes, at first, detect when can realize all optical element face shapes of system, avoided detecting one by one in the existing surface testing method trouble that needs the frequent standard lens; Secondly, owing to need not the standard of replacement camera lens in detecting, can detect the optical element face shape of various curvature and bore, not be subjected to the restriction of standard lens bore and radius-of-curvature; At last, the method detects in the final stage of optics assembling, and the optical element face shape error that causes in the optics assembling process also detects in the lump, has improved the accuracy that detects.

The invention provides a kind of each optical element surface testing method of optical system based on wave aberration, wave aberration by detection optical system, determine the face shape of each optical element in the optical system, can be at last assembling stage, directly by the final optical system wavefront aberration of measuring, obtain the face graphic data of each optical element of optical system, and then can eliminate system's wave aberration that the lens face shape deflection error produces.The method is particularly useful for the optical system that the face graphic data can not Measurement accuracy, has avoided the face graphic data to detect error and has caused follow-up improper operation of debuging in the process, can improve the imaging of optical systems quality.

Description of drawings

Fig. 1 is based on the process flow diagram of each face surface testing method of optical system of wave aberration;

Fig. 2 realizes one embodiment of the present of invention.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail.

Illustrate such as Fig. 1, the invention provides a kind of detection method of each the optical element face shape of optical system based on wave aberration, each optical element face shape of described optical system is detected and be may further comprise the steps:

Step S1: each optical element of optical system is slightly debug, optical system wavefront aberration can effectively be detected by the wave aberration pick-up unit;

Step S2: the locus for the treatment of each optical element of debuging is adjusted, and measures the wave aberration of optical system under each location status, simultaneously the location status of recording optically element and the optical system wavefront aberration under this state;

Step S3: with optical system wavefront aberration input processor corresponding under the position of optical element state that records among the step S2 and this state, calculate the face shape of each optical element.

Described wave aberration pick-up unit is interferometer, or other can be used for the checkout equipment that wave aberration detects.

The mode of the locus adjustment of described optical element is to treat each optical element of optical system of debuging to carry out translation, inclination and rotation.

Described processor can be computing machine, or is used for the processor of mathematical operation.

The present invention is described in detail the detection method of the optical system face shape based on wave aberration provided by the present invention as an example of optical system shown in Figure 2 example.In Fig. 2, the optical element of optical system comprises four lens, differentiates from left to right and is designated lens 1, lens 2, lens 3 and lens 4.

The parameter of system is:

Effective focal length: 159.07

F number: 1.60

Operation wavelength: λ=632.8nm

Each lens and face parameter are as shown in Table 1.

Each lens of table 1 optical system and face parameter

The face shape wave aberration of lens 1, lens 2, lens 3 and lens 4 is expressed as respectively W ₁, W ₂, W ₃And W ₄The spherical wave W that object point O sends ₀Imaging point P behind lens 1, lens 2, lens 3 and lens 4, then the wave aberration W of imaging point P _pCan be expressed as:

W _p＝W ₀+W ₁K ₁+W ₂K ₂+W ₃K ₃+W ₄K ₄ (1)

K wherein _i(i=1,2,3,4) are the face shape wave aberration of lens i shared weight in whole optical system wavefront aberration, and are relevant with each position of optical element state with the optical system structure parameter.When position of optical element is adjusted, K _iChange thereupon, can utilize optical design software to pass through optical system structure parameter and the acquisition of optical element location parameter.

As shown in Figure 1, at first to lens 1, lens 2, the optical system that lens 3 and lens 4 form is slightly debug, and makes the wave aberration W of imaging point P _pCan effectively be detected.Then, adjust the locus of each optical element, measure the wave aberration of optical system under each location status, simultaneously the location status of recording optically element and the optical system wavefront aberration under this state.The position of optical element of record is input to processor, utilizes optical design software can obtain weight coefficient K by the optical system structure parameter _i(i=1,2,3,4).

According to formula (1), optical system wavefront aberration is carried out n time measure, can get formula (2).

$\left\{\begin{array}{c}{W}_0+W_1{K}_{11}+W_2{K}_{12}+W_3{K}_{13}+W_4{K}_{14}=W_{p1}\\ W_0+W_1{K}_{21}+W_2{K}_{22}+W_3{K}_{23}+W_4{K}_{24}={\mathrm{<figure-callout\; id="2"\; label="W\; p"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">W</figure-callout>}}_p\\ .\\ .\\ .\\ W_0+W_1{K}_{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">n</figure-callout>}1}+W_2{K}_{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">n</figure-callout>}2}+W_3{K}_{\mathrm{<figure-callout\; id="3"\; label="n"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">n</figure-callout>}3}+W_4{K}_{\mathrm{<figure-callout\; id="4"\; label="n"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">n</figure-callout>}4}=W_{\mathrm{pn}}\end{array}\right.---\left(2\right)$

W wherein _Pj(j=1,2 ..., be imaging point P to be carried out the j time measure the system's wave aberration that obtains, K n) _JiBe i optical component surface shape wave aberration shared weight in whole optical system wavefront aberration in measuring for the j time, j=1,2 ..., n, i=1,2,3,4.Order

$K=\left[\begin{array}{ccccc}1& K_{11}& K_{12}& K_{13}& K_{14}\\ 1& K_{21}& K_{22}& K_{23}& K_{24}\\ & & \&CenterDot;& & \\ & & \&CenterDot;& & \\ & & \&CenterDot;& & \\ 1& K_{n1}& K_{n2}& K_{n3}& {\mathrm{<figure-callout\; id="4"\; label="k\; n"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">k</figure-callout>}}_n\end{array}\right]$

$W_P=\left[\begin{array}{c}{W}_{p1}\\ {\mathrm{<figure-callout\; id="2"\; label="W\; p"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">W</figure-callout>}}_p\\ .\\ .\\ .\\ W_{\mathrm{pn}}\end{array}\right]$

$W=\left[\begin{array}{c}{W}_0\\ W_1\\ W_2\\ W_3\\ {\mathrm{<figure-callout\; id="4"\; label="W"\; filenames="HDA00003510002600012.png"\; state="\{\{state\}\}">W</figure-callout>}}_4\end{array}\right]$

Utilize least square method solution formula (1), the face shape wave aberration W that can obtain optical element in the optical system is:

W＝(K ^TK) ^-1K ^TW _p (3)

K is by weights K in the formula _JiThe weight matrix that forms, K ^TThe transposed matrix of K, W _pIt is the vector of n measuring system wave aberration composition.According to weight matrix K and n measuring system wave aberration W _p, utilize the mathematical operation function of processor, can be calculated the face shape wave aberration W of each optical element of optical system by formula (3).

Those of ordinary skill in the art will be appreciated that, above embodiment illustrates the present invention, and be not as limitation of the invention, as long as in connotation scope of the present invention, the above embodiment is changed, and modification all will drop in the scope of claims of the present invention.

Claims (4)

1. detection method based on each optical element face shape of optical system of wave aberration, it is characterized in that: each optical element face shape detecting step of described optical system is as follows:

Step S1: each optical element of optical system is slightly debug, optical system wavefront aberration can effectively be detected by the wave aberration pick-up unit;

Step S2: the locus to each optical element is adjusted, and measures the wave aberration of optical system under each location status, simultaneously the location status of recording optically element and the optical system wavefront aberration under this state;

Step S3: with corresponding optical system wavefront aberration input processor under the position of optical element state of record and this state, calculate the face shape of each optical element.

2. the detection method of each optical element face shape of optical system as claimed in claim 1, it is characterized in that: described wave aberration pick-up unit is interferometer, or other can be used for the equipment that wave aberration detects.

3. the detection method of each optical element face shape of optical system as claimed in claim 1, it is characterized in that: described locus adjustment to each optical element is that each optical element is carried out translation, inclination or rotation.

4. the detection method of each optical element face shape of optical system as claimed in claim 1, it is characterized in that: described processor is computing machine, or is used for the processor of mathematical operation.

Images