LC-SLM error compensation method and aspheric surface-type detection method thereof

Abstract

The present invention relates to the optics aspheric precision measurement field, and relates to an aspheric surface-type detection method based on the LC-SLM error compensation and digital phase shift technology. The ZEMAX software is employed to perform optics tracking to obtain the ideal wave aberration of an optics system, a series of orthogonal Zernike polynomials are employed to represent the wave aberration, the corresponding computer generated hologram is obtained and is loaded on the LC-SLM, the residual error iteration method is employed to reduce the influence of the LC-SLM curvature error, the edge field effect and the like and improve the wavefront simulation precision of the LC-SLM, and the convergent lens playing the compensation effect and digital phase shift and interference fringe analysis technology are combined to greatly improve the measurement dynamic range and realize the real-time detection of the large aspheric surface degree surface type.

Description

【Technical field】 [0001] The invention relates to the field of precision measurement of optical aspheric surfaces, and relates to an LC-SLM error compensation and an aspheric surface type detection method. 【Background technique】 [0002] Optical aspheric elements have significant advantages in correcting aberrations, improving image quality, and simplifying systems. However, due to the complexity and variety of optical aspheric shapes, their processing and measurement are much more difficult than spherical optical elements. Computational hologram (CGH) has become an important compensation element in the detection of aspheric compensation. However, if the computational hologram relies on ion beam processing equipment, not only the measurement accuracy cannot meet the requirements, but also different types of aspheric surfaces require different computational holograms for compensation, which has poor flexibility. [0003] With the development of liquid crystal display technol...

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Problems solved by technology

[0004] In order to obtain accurate surface information, phase-shifting interferometry technology is introduced in many aspheric surface-type measurements, such as Zygo's Fizeau phase-shifting interferometer, the principle is to use the piezoelectric effect of PZT to generate a small displacement, so as to achieve phase shifting , but the cost of this method is high, and the accuracy is greatly affected by factors such as ambient temperature and vibration

Moreover, the dynamic range that can be measured by many zero point measurement methods is only a few wavelengths, and the detection dynamic range is relatively small, which cannot meet the measurement requirements.

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