CN103226059A

CN103226059A - Wavefront measuring device and method for optical system

Info

Publication number: CN103226059A
Application number: CN2013101221168A
Authority: CN
Inventors: 陈永权; 段亚轩; 李坤; 赵建科; 胡丹丹; 赛建刚; 龙江波
Original assignee: XiAn Institute of Optics and Precision Mechanics of CAS
Current assignee: XiAn Institute of Optics and Precision Mechanics of CAS
Priority date: 2013-04-09
Filing date: 2013-04-09
Publication date: 2013-07-31

Abstract

The invention relates to a wavefront measuring device and a measuring method of an optical system, wherein the wavefront measuring device of the optical system comprises a laser, a small lens array, an imaging lens array, a CCD array and an acquisition control computer; the small lens array, the imaging lens array and the CCD array are sequentially arranged on an emergent light path of the laser; the CCD is electrically connected with the acquisition control computer. The invention provides an optical system wavefront measuring device and a measuring method which can quickly measure the system wavefront of a large-aperture optical system without adopting a large-aperture optical element.

Description

Optical system Wavefront measuring apparatus and measuring method

Technical field

The invention belongs to the optical detection field, relate to a kind of optical system Wavefront measuring apparatus and measuring method, relate in particular to a kind of heavy-caliber optical system Wavefront measuring apparatus.

Background technology

The wavefront of optical system is an important technology index after its system is debug, and its quality directly affects the image quality or the transmission performance of system.Along with the continuous development in China's aerospace industry, military project target range, the utilization of heavy-caliber optical system is more and more, and following, the difficulty of test of wavefront is also more and more higher.

Existing method of testing comprises following several:

1) adopt laser interferometer that the wavefront of optical system is tested, but the restriction of bore of Stimulated Light interferometer (interferometer of China's bore maximum is Ф 800mm at present) or standard reflection aperture of mirror, the wavefront measurement bore is also limited thereupon.Simultaneously, development large-caliber laser interferometer, used optical elements of large caliber difficulty of processing is big in the system, and cost is very expensive, and is less economical.

2) adopt small-bore laser interferometer scanning survey, it is bigger that this method is influenced by wavefront splicing precision, and when simultaneously heavy-caliber optical system being tested, system adjusts relative complex, and Measuring Time is longer.

3) adopt Hartmann's wavefront measurement system that the wavefront of heavy-caliber optical system is tested, the method need be developed a bore the contract beam system suitable with optical system bore to be measured, and expense is also higher relatively.

Summary of the invention

In order to solve the problems referred to above that exist in the background technology, the present invention proposes a kind of optical system Wavefront measuring apparatus and measuring method that does not adopt optical elements of large caliber to measure system's wavefront of heavy-caliber optical system fast.

Technical solution of the present invention is: the invention provides a kind of optical system Wavefront measuring apparatus, its special character is: described optical system Wavefront measuring apparatus comprises laser instrument, lenslet array, imaging len array, ccd array and acquisition controlling computing machine; Described lenslet array, imaging len array and ccd array are successively set on the emitting light path of laser instrument; Described CCD and acquisition controlling computing machine are electrical connected.

The imaging object plane of above-mentioned imaging len array is the focal plane of lenslet array.

Above-mentioned lenslet array comprises four lenslets at least; Described imaging len array comprises at least one imaging len; The imaging object plane of described imaging len array is the focal plane of the lenslet in the lenslet array.

Above-mentioned ccd array is arranged on the imaging surface place of imaging len array.

Above-mentioned ccd array comprise with the imaging len array in the corresponding to CCD of number of imaging len.

Above-mentioned laser instrument comprises optical fiber pigtail, and the fibre core of described optical fiber pigtail is less than the diffraction-limited of optical system to be measured.

The fibre core of above-mentioned optical fiber pigtail is less than one times of diffraction-limited of optical system to be measured.

A kind of measuring method that is used for the optical system Wavefront measuring apparatus, its special character is: described measuring method may further comprise the steps:

1) opens laser instrument and produce laser;

2) the resulting laser of step 1) is injected optical system to be measured and forms plane wave;

3) by lenslet array to step 2) formed plane wave carries out light beam and focuses on, and forms the array focal spot;

4) by the imaging len array the formed array focal spot of step 3) is carried out imaging, form light spot image;

5) by the ccd array synchronous acquisition by the formed light spot image of step 4);

6) by the acquisition controlling computing machine interpretation is carried out in the position of the light spot image after gathering, and calculate the wavefront slope that ccd array collects;

7) wavefront for the treatment of the photometry system restores.

Advantage of the present invention is:

1, adopt measurement mechanism provided by the present invention, can carry out the wavefront test of heavy-caliber optical system, be particularly useful for the system wavefront test of bore greater than the optical system of 1m, the system development cost is relatively low;

2, adopt wavefront slope that wavefront is restored, have the advantage that Hartmann wave front sensor is measured, but the wavefront of real time dynamic measurement heavy-caliber optical system, the measuring accuracy height;

3, according to the size and the beam sampling requirement of measuring bore, can have at design lenslet array and imaging len array, avoid using in the test macro optical elements of large caliber.

Description of drawings

Fig. 1 is the structural representation of optical system Wavefront measuring apparatus provided by the present invention;

Wherein:

The 1-laser instrument; 2-optical system to be measured; The 3-lenslet array; 4-imaging len array; The 5-CCD array; 6-acquisition controlling computing machine.

Embodiment

The present invention comprises laser instrument 1, optical system to be measured 2, lenslet array 3, imaging len array 4, ccd array 5, acquisition controlling computing machine 6 as shown in Figure 1, is provided with wave front restoration software in the acquisition controlling computing machine 6.Lenslet array 3, imaging len array 4 and ccd array 5 are successively set on the emitting light path of laser instrument 1; Optical system 2 to be measured places between laser instrument 1 and the lenslet array 3; Ccd array 5 is electrical connected with acquisition controlling computing machine 6.

The imaging object plane of imaging len array 4 is focal planes of lenslet array 3; Lenslet array 3 comprises four lenslets at least; Imaging len array 4 comprises at least one imaging len; The imaging object plane of imaging len array 4 is focal planes of the lenslet in the lenslet array 3.

Ccd array 5 is arranged on the imaging surface place of imaging len array 4; Ccd array 5 comprise with the imaging len array in the corresponding to CCD of number of 4 imaging len.

Laser instrument 1 comprises optical fiber pigtail, and the fibre core of optical fiber pigtail is less than the diffraction-limited of optical system to be measured, especially less than one times of diffraction-limited of optical system to be measured.

The present invention is when concrete work, its working method is: open laser instrument 1, laser is exported by optical fiber pigtail, the fibre core of optical fiber is less than one times of diffraction-limited of optical system 2 to be measured, laser is injected optical system 2 to be measured, form plane wave, focus on by 3 pairs of light beams behind optical system 2 collimations to be measured of lenslet array, form the array focal spot, by imaging len array 4 to the array focal spot imaging in its corresponding visual field, by ccd array 5 synchronous acquisition light spot images, the facula position of each subimage after gathering is carried out interpretation, treat the wavefront of photometry system and restore by calculating wavefront slope that ccd array 5 collects.

Claims

1. An optical system wavefront measuring device is characterized in that: said optical system wavefront measuring device comprises a laser, a small lens array, an imaging lens array, a CCD array and an acquisition control computer; said small lens array, an imaging lens array And the CCD array is sequentially arranged on the outgoing light path of the laser; the CCD array is electrically connected with the acquisition control computer.

2 . The optical system wavefront measurement device according to claim 1 , wherein the imaging plane of the imaging lens array is the focal plane of the small lens array. 3 .

3. The optical system wavefront measuring device according to claim 2, characterized in that: the small lens array comprises at least four small lenses; the imaging lens array comprises at least one imaging lens; the imaging of the imaging lens array The object plane is the focal plane of the lenslets in the lenslet array.

4. The optical system wavefront measuring device according to claim 3, characterized in that: the CCD array is arranged at the imaging plane of the imaging lens array.

5 . The optical system wavefront measuring device according to claim 4 , wherein the CCD array includes CCDs corresponding to the number of imaging lenses in the imaging lens array. 6 .

6. The optical system wavefront measurement device according to any one of claims 1-5, wherein the laser comprises a fiber pigtail, and the core of the fiber pigtail is smaller than the diffraction limit of the optical system to be measured .

7. The optical system wavefront measuring device according to claim 6, characterized in that: the core of the optical fiber pigtail is smaller than one time of the diffraction limit of the optical system to be measured.

8. A measurement method for the optical system wavefront measurement device according to any one of claims 1-7, characterized in that: the measurement method comprises the following steps:

1) Turn on the laser to generate laser light;

2) Inject the laser light obtained in step 1) into the optical system to be tested and form a plane wave;

3) The plane wave formed in step 2) is focused by the small lens array to form the focal spot of the array;

4) Imaging the focal spot of the array formed in step 3) by the imaging lens array to form a spot image;

5) The spot image formed in step 4) is collected synchronously by the CCD array;

6) The acquisition control computer interprets the position of the acquired spot image, and calculates the wavefront slope acquired by the CCD array;

7) Restoring the wavefront of the optical system under test.