Method for realizing programmable multi-wave lateral shearing interferometer

Abstract

The invention discloses a method for realizing a programmable multi-wave lateral shearing interferometer. The method comprises the following steps: (1) determining the requirements on the sensitivity and dynamic range; (2) determining an operating mode comprising a three-wave lateral shearing interferometer / four-wave lateral shearing interferometer / six-wave lateral shearing interferometer; (3) calculating the grating complex amplitude transmission distribution needed by the interferometer; (4) generating a diffraction grating of the multi-wave lateral shearing interferometer by using a pure-phase spatial light modulator; (5) taking an image sensor as a receiving screen to be arranged on an emergent light path, performing coherent superposition on the reflected light reflected by the pure-phase spatial light modulator to form interference fringes on the receiving screen, calculating the interference fringes obtained by detecting the image sensor so as to acquire the wavefront slope information, and further restoring the wavefront; and (6) changing the operating mode by virtue of programming, and changing the sensitivity and dynamic range of the four-wave lateral shearing interferometer. The programmable function of measuring the dynamic range and sensitivity is realized, and convenience is provided for switch among the three-wave lateral shearing interferometer, the four-wave lateral shearing interferometer and the six-wave lateral shearing interferometer four-wave lateral shearing interferometer.

Description

technical field [0001] The invention relates to a method for realizing a programmable multi-wave transverse shearing interferometer, which realizes the functions of generating a grating through programming and changing the dynamic range and sensitivity of the interferometer through programming, and at the same time, it is also used for three-wave, four-wave and six-wave transverse shearing. Switching between cutting interferometers provides convenience and can play their respective advantages. Background technique [0002] Wavefront sensors have been widely used in the fields of surface detection of optical components, optical adaptive systems, and beam purification. Commonly used wavefront sensors include interferometer wavefront sensors, Shaker-Hartmann wavefront sensors, and the like. [0003] The Shack-Hartmann wavefront sensor makes the wave surface to be measured incident on the microlens array, and the detector is placed on the focal plane of the microlens array to r...

AI Technical Summary

Problems solved by technology

[0008] The traditional amplitude grating is made of metal chromium, and the phase grating is etched from fused silica. Due to the influence of the substrate surface error, material non-uniformity and processing error during the etching process, the diffraction efficiency of the traditional diffraction grating is different from that of the ideal situation. There is a certain error in comparison, and once the grating is formed, it does not have variability, that is, the grating period and shape are not changeable, which limits the flexibility and accuracy of the interferometer to a certain extent.

[0009] The technical problems to be solved by the present invention are: 1. In the traditional four-wave transverse shearing interferometer, the grating period of the diffraction grating is invariable. To change the sensitivity and dynamic range of the interferometer, only by changing the distance between the CCD and the grating. This will not only increase the loss of the interferometer, but also greatly reduce the stability of the system

2. In the traditional four-wave transverse shearing interferometer, the grating shape of the diffraction grating is not changeable, and it is necessary to switch between the four-wave transverse shearing interferometer, the three-wave transverse shearing interferometer and the six-wave transverse shearing interferometer , can only be realized by replacing the grating in the system, the operation process is cumbersome and easy to damage the system stability

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