Detachable and reconfigurable phase mask and wavefront encoding imaging system

Abstract

The invention relates to a detachable and reconfigurable phase mask and a wave-front coding and imaging system on the basis of the phase mask. Two cosine functions with relative displacement are superimposed to form a phase mask function corresponding to the detachable and reconfigurable phase mask, a one-dimensional function expression of the detachable and reconfigurable phase mask is shown, an alpha, an m<1> and an m<2> in the one-dimensional function expression are parameters of a phase distribution function, an x is a normalized coordinate, a value of the x is larger than or equal to -1 and is smaller than or equal to 1, and a value of the offset m<1> and a value of the offset m<2> are respectively larger than or equal to -1 and are smaller than or equal to 1. The detachable and reconfigurable phase mask and the wave-front coding and imaging system on the basis of the phase mask have the advantages that the depth of the focus of the system can be effectively expanded by the detachable and reconfigurable phase mask, and both the out-of-focus sensitivity and the bandwidth of the wave-front coding and imaging system can be adjusted.

Description

technical field [0001] The invention belongs to the field of optics, and relates to a phase mask and a wavefront coding imaging system based on the phase mask. Background technique [0002] The depth of field of extended optical systems has always been a hotspot in academic research. Since the mid-1980s, although various methods have been proposed for depth of field expansion, it was not until Dr. Dowski and Professor Cathey of the University of Colorado in the United States proposed the wavefront in 1995. After the concept of coding, the extension of depth of field had a real breakthrough. [0003] Taking the one-dimensional optical system as an example, its defocus optical transfer function OTF can be obtained through the autocorrelation operation of the generalized pupil function, as follows: [0004] H ( u , W 20 ) = 1 ...

AI Technical Summary

Problems solved by technology

In addition, the existing research on the wavefront coding system is focused on the defocus invariance, and there are relatively few studies on the frequency characteristics of the system (such as whether the bandwidth is adjustable or not)

However, since most digital imaging systems, including wavefront encoding systems, are image detector limited, there are spectral aliasing effects caused by undersampling that degrade image quality

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