Lensless diffraction imaging method based on complementary random sampling

Abstract

A lensless diffraction imaging method based on complementary random sampling is characterized in that a group of binary random sampling screens with complementary characteristics is introduced; the group of binary random sampling screens is arranged between a to-be-tested object and a record plane in sequence, and intensity patterns of object waves passing through the sampling screens on the record plane are sequentially recorded; the complex amplitude distribution of to-be-tested object waves is recovered from the recorded intensity patterns, and the digital diffraction operation is conducted using the recovered complex amplitude distribution, so as to obtain the diffraction imaging of the to-be-tested object at any spatial position. According to the method, the complementary random sampling screens are inserted between the object and the record plane, so that the accuracy and the iteration efficiency of phase retrieval are greatly improved; meanwhile, wavefront sampling loss caused by the binary random sampling in the traditional method can be effectively eliminated. In addition, as the iteration operation process is only applied to the sampling plane and the record plane, the method is suitable for general complex-valued objects and does not place special limits on the object.

Description

technical field [0001] The invention relates to a lensless diffraction imaging method, which belongs to the technical field of diffraction imaging. Background technique [0002] Lensless Coherent Diffraction Imaging (CDI) (see Document 1) is a technology that uses the diffraction intensity pattern of the object wave to calculate the complex amplitude distribution of the object wave wavefront. There are important practical applications in other fields. The key problem of CDI technology is how to recover the complex amplitude information (including amplitude information and phase information, mainly the recovery of phase information) of the object wave front from the diffraction intensity pattern of the object wave. In order to solve the problem of recovering the complex amplitude of the wavefront, many methods have been proposed. Among them, holographic interferometry technology is the most commonly used method, such as on-axis or off-axis holography (see literature 2-docum...

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Problems solved by technology

Although the compressed sensing algorithm (see literature 33) can also realize diffraction imaging based on this kind of sparsely sampled data, the redundancy of the target object puts forward higher requirements

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