CN103207022A - Calibration method for eliminating rotating asymmetrical errors in phase retrieval test process - Google Patents

Abstract

The invention provides a calibration method for eliminating rotating asymmetrical errors in a phase retrieval test process and relates to the field of system error calibration in an optical test process. The method comprises the steps of placing an optical amplification system and a sensor on a fine adjustment mechanism, enabling the fine adjustment mechanism for 360 degrees, performing uniformly-spaced rotating measurement, and obtaining measurement results of corresponding wavefronts; performing average calculating operation on the wavefront measurement results, and enabling average results not to contain rotating asymmetrical error information of the measured wavefronts; enabling the wavefront measurement results obtained after rotation each time to respectively subtract the obtained average results so as to obtain the rotating asymmetrical error information of the measured wavefronts in rotating states; performing coordinate correction on the obtained rotating asymmetrical error information of the measured wavefronts in every rotating state, enabling the rotating asymmetrical error information to be unified under an identical coordinate system to be averaged, obtaining the rotating asymmetrical error information in the measured wavefronts, and restraining random errors. The rotating asymmetrical errors introduced by the optical amplification system are eliminated through the method.

Description

Eliminate the scaling method of rotation non-symmetric error in the phase retrieval test process

Technical field

The present invention relates to the demarcation field of systematic error in the optic test process, be specifically related to eliminate in a kind of phase retrieval test process the scaling method of rotation non-symmetric error.

Background technology

It is a kind of optical testing technology that is widely used that the application phase recovery technique carries out the optical wavefront test.It utilizes the mathematical relation between asterism image and the optical wavefront, by collection analysis asterism image, obtains optical wavefront information.The asterism size of images is generally very little, in the image acquisition process of reality, can be subjected to the restriction of sensor pixels size, in order to obtain to have enough sampling rate asterism images, generally need before sensor, add optical amplification system, after being amplified, the asterism image is imaged onto on the sensor.And actual use optical amplification system is not perfect optical system, and its error can be to test result drawing-in system error.The invention provides a kind of method of demarcation of systematic error

Summary of the invention

In order to solve problems of the prior art, the invention provides the scaling method of eliminating the rotation non-symmetric error in a kind of phase retrieval test process, can demarcate the rotation non-symmetric error that optical amplification system in the phase retrieval test process is introduced, obtain in the tested wavefront non-rotating symmetric information accurately.

The technical scheme that technical solution problem of the present invention adopts is as follows:

Eliminate the scaling method of rotation non-symmetric error in the phase retrieval test process, this method comprises the steps:

Step 1: optical amplification system and sensor are placed on the accurate adjusting mechanism, serve as 360 ° of the accurate adjusting mechanisms of axle rotation with the chief ray that passes optical amplification system, uniformly-spaced rotation collection image is measured, and the image of gathering is that the frame of reference obtains corresponding wavefront measurements respectively with sensor coordinates;

Step 2: the result of wavefront measurement in the step 1 is averaged computing, do not contain the rotation non-symmetric error information of tested wavefront in this average result;

Step 3: each postrotational wavefront measurements in the step 1 deducted respectively obtain average result in the step 2, to obtain in the step 1 rotation non-symmetric error information of tested wavefront under the rotation status:

Step 4: the rotation non-symmetric error information of tested wavefront under each rotation status that obtains in the step 3 is carried out the coordinate correction, its unification is averaged under the same coordinate system, this mean value is rotation non-symmetric error information in the tested wavefront.

The invention has the beneficial effects as follows: the present invention eliminates the rotation non-symmetric error that optical amplification system is introduced by this method.

Description of drawings

Gather the device of asterism image in Fig. 1 phase retrieval test process.

Wherein, 1 is optical amplification system, and 2 is sensor, and 3 is accurate five dimension adjusting mechanisms, and 4 is optical axis, and 5 is optical system for collecting.

Embodiment

Below in conjunction with drawings and Examples the present invention is described in further details.

Step 1: as shown in Figure 1, optical system for collecting 5 comprises optical amplification system 1 and sensor 2, optical system for collecting 5 is installed on the accurate five dimension adjusting mechanisms 3, light beam is imaged onto on the sensor 2 through optical amplification system 1, its chief ray is defined as optical axis 4, these accurate five dimension adjusting mechanisms 3 can carry out 360 ° of rotations around optical axis 4 with optical system for collecting 5, sensor coordinate system is initial point with the intersection point of optical axis 4 and sensor, and the coordinate origin of sensor immobilizes in rotary course; The coordinate system of sensor is on the receiving plane of sensor.The optical system for collecting dextrorotation is gone to 0 °, 60 °, 120 °, 180 °, 240 ° and 300 ° measure, obtain the measurement result to wavefront respectively;

Coordinate with sensor is benchmark, and sensor coordinate system rotates with accurate adjusting mechanism.Be equivalent to tested wavefront and taken place to be rotated counterclockwise, the following formula of wavefront test result of acquisition is represented:

$\left\{\begin{array}{c}{W}_0=W_{\mathrm{sys}}+W_{\mathrm{rot}}+W_{\mathrm{nrot}}^0\\ W_{60}=W_{\mathrm{sys}}+W_{\mathrm{rot}}+W_{\mathrm{nrot}}^{60}\\ W_{120}=W_{\mathrm{sys}}+W_{\mathrm{rot}}+W_{\mathrm{nrot}}^{120}\\ W_{180}=W_{\mathrm{sys}}+W_{\mathrm{rot}}+W_{\mathrm{nrot}}^{180}\\ W_{240}=W_{\mathrm{sys}}+W_{\mathrm{rot}}+W_{\mathrm{nrot}}^{240}\\ W_{300}=W_{\mathrm{sys}}+W_{\mathrm{rot}}+W_{\mathrm{nrot}}^{300}\end{array}\right.,---\left(1\right)$

W wherein ₀For the optical system for collecting dextrorotation goes to the measurement result of 0 ° of coordinate time, W ₆₀For the optical system for collecting dextrorotation goes to the measurement result of 60 ° of coordinate times, W ₁₂₀For the optical system for collecting dextrorotation goes to the measurement result of 120 ° of coordinate times, W ₁₈₀For the optical system for collecting dextrorotation goes to the measurement result of 180 ° of coordinate times, W ₂₄₀For the optical system for collecting dextrorotation goes to the measurement result of 240 ° of coordinate times, W ₃₀₀For the optical system for collecting dextrorotation goes to the measurement result of 300 ° of coordinate times, W _SysBe optical system error, W _RotBe the rotation balanced error information in the tested wavefront, Be the non-rotating balanced error information of tested wavefront when being rotated counterclockwise to 0 ° of measurement of coordinates,

Be the non-rotating balanced error information of tested wavefront when being rotated counterclockwise to 60 ° of measurement of coordinates, Be the non-rotating balanced error information of tested wavefront when being rotated counterclockwise to 120 ° of measurement of coordinates,

Be the non-rotating balanced error information of tested wavefront when being rotated counterclockwise to 180 ° of measurement of coordinates, Be the non-rotating balanced error information of tested wavefront when being rotated counterclockwise to 240 ° of measurement of coordinates,

Be the non-rotating balanced error information of tested wavefront when being rotated counterclockwise to 300 ° of measurement of coordinates.

Step 2: the result who repeatedly measures in the step 1 is averaged computing, calculate the average result repeatedly measured, do not contain the rotation non-symmetric error information of tested wavefront in this average result substantially.

Non-symmetric error in the wavefront information can be expressed as the form into Fourier series:

W _nrot=∑R1(ρ)cos(nθ)+R2(ρ)sin(nθ)， (2)

ρ wherein, θ is polar coordinates, n 〉=1 utilizes the characteristic of Fourier series to obtain:

$W_{\mathrm{nrot}}^0+W_{\mathrm{nrot}}^{60}+W_{\mathrm{nrot}}^{120}+W_{\mathrm{nrot}}^{180}+W_{\mathrm{nrot}}^{240}+W_{\mathrm{nrot}}^{300}\≈0.---\left(3\right)$

Repeatedly wheel measuring result's mean value is:

W=W _sys+W _rot。(4)

Step 3: each postrotational wavefront measurements in the step 1 deducted respectively obtain average result in the step 2, to obtain the rotation non-symmetric error information of tested wavefront under the current rotation status.

$\left\{\begin{array}{c}\stackrel{\‾}{W}-W_0=W_{\mathrm{nrot}}^0\\ \stackrel{\‾}{W}-W_{60}=W_{\mathrm{nrot}}^{60}\\ \stackrel{\‾}{W}-W_{120}=W_{\mathrm{nrot}}^{120}\\ \stackrel{\‾}{W}-W_{180}=W_{\mathrm{nrot}}^{180}\\ \stackrel{\‾}{W}-W_{240}=W_{\mathrm{nrot}}^{240}\\ \stackrel{\‾}{W}-W_{300}=W_{\mathrm{nrot}}^{300}\end{array}\right.---\left(5\right)$

Step 4, the rotation non-symmetric error information of tested wavefront under each rotation status that obtains in the step 3 is carried out the coordinate correction, its unification is averaged under the same coordinate system, to reduce the uncertainty of measurement result, this mean value result is rotation non-symmetric error information in the tested wavefront.

$W_{\mathrm{nrot}}=\frac{W_{\mathrm{nrot}}^0+{\tilde{W}}_{\mathrm{nrot}}^{60}+{\tilde{W}}_{\mathrm{nrot}}^{120}+{\tilde{W}}_{\mathrm{nrot}}^{180}+{\tilde{W}}_{\mathrm{nrot}}^{240}+{\tilde{W}}_{\mathrm{nrot}}^{300}}{6}---\left(6\right)$

Wherein

For

Carry out the revised result of coordinate, unified its coordinate system is consistent with the coordinate system of 0 ° of tested wavefront;

For

Carry out the revised result of coordinate, unified its coordinate system is consistent with the coordinate system of 0 ° of tested wavefront, For Carry out the revised result of coordinate, unified its coordinate system is consistent with the coordinate system of 0 ° of tested wavefront,

For

Carry out the revised result of coordinate, unified its coordinate system is consistent with the coordinate system of 0 ° of tested wavefront, For

Carry out the revised result of coordinate, unified its coordinate system is consistent with the coordinate system of 0 ° of tested wavefront.This operation will help to suppress the stochastic error in the calibration process.

Claims (3)

1. eliminate the scaling method of rotation non-symmetric error in the phase retrieval test process, it is characterized in that this method comprises the steps:

Step 1: optical amplification system and sensor are placed on the accurate adjusting mechanism, serve as 360 ° of the accurate adjusting mechanisms of axle rotation with the chief ray that passes optical amplification system, uniformly-spaced rotation collection image is measured, and the image of gathering is that the frame of reference obtains corresponding wavefront measurements respectively with sensor coordinates;

Step 2: the result of wavefront measurement in the step 1 is averaged computing, do not contain the rotation non-symmetric error information of tested wavefront in this average result;

Step 3: each postrotational wavefront measurements in the step 1 deducted respectively obtain average result in the step 2, to obtain in the step 1 rotation non-symmetric error information of tested wavefront under the rotation status;

Step 4: the rotation non-symmetric error information of tested wavefront under each rotation status that obtains in the step 3 is carried out the coordinate correction, its unification is averaged under the same coordinate system, this mean value is rotation non-symmetric error information in the tested wavefront.

2. eliminate the scaling method of rotation non-symmetric error in the phase retrieval test process as claimed in claim 1, it is characterized in that the sensor coordinate system described in the step 1 rotates with accurate adjusting mechanism.

3. eliminate the scaling method of rotation non-symmetric error in the phase retrieval test process as claimed in claim 1 or 2, it is characterized in that, sensor coordinate system described in the step 1 is initial point with the intersection point of chief ray and sensor, and the coordinate origin of sensor immobilizes in rotary course.

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