Wavefront Coding Optimal Phase Mask Parameter Acquisition Based on Filter Stabilization

Abstract

The invention relates to a wavefront coding optimal phase mask plate parameter obtaining method based on filter stability. The method comprises the steps that (1) a restoration filter is constructed by an OTF with the defocusing amount being zero after a phase plate is arranged; (2) according to the restoration filter, an estimation of an optical transfer function corresponding to each defocusing amount is calculated, the difference between the estimation of the optical transfer function and a diffraction limitation transfer function Hd1 of a traditional system, and an RMS error of the difference is obtained in the defocusing parameter dimension; (3) the RMS error is integrated so as to obtain a quantifiable objective function; (4) iterative optimization is conducted through an global optimization algorithm continually, and the optimal phase plate parameter giving consideration to a restoration filtering process is found. The wavefront coding optimal phase mask plate parameter obtaining method based on the filter stability can not only achieve invariable defocusing of the system, but also enable restored images to be close to diffraction limitation effects as far as possible.

Description

technical field [0001] The invention belongs to the field of optics, and relates to a method for acquiring parameters of a wavefront encoding imaging system, in particular to a method for acquiring parameters of a wavefront encoding optimal phase mask plate based on filter stabilization. Background technique [0002] Extending the depth of field of optical imaging systems has always been a research hotspot in the academic circles. Reducing the relative aperture of the system can achieve the effect of extending the depth of field, but it will seriously lose luminous flux and resolution, so it is not practical. Since the mid-1980s, although various methods have been proposed to extend the depth of field of the imaging system, it was not until Dr. E.R. Dowski and Professor Cathey of the University of Colorado in the United States proposed the concept of wavefront encoding in 1995 that the depth of field extension had no effect. A real breakthrough. [0003] By adding a cubic ...

AI Technical Summary

Problems solved by technology

In other words, the traditional optimization process only achieves optical optimization, but does not give clear requirements for the restoration algorithm (such as the selection of filter parameters, etc.), so it cannot be called optical / digital joint optimization

Images