All-solid digital holography imaging system capable of reducing speckle noise

Abstract

The invention discloses an all-solid digital holography imaging system capable of reducing speckle noise, and belongs to the technical field of optical diffraction imaging and digital holography. The all-solid digital holography imaging system capable of reducing the speckle noise comprises a hologram shooting light path, a spatial light modulator, a sample to be detected, an image sensor and a computer. The reference light in the hologram shooting light path is directly incident to the image sensor, the object light in the hologram shooting light path passes through the spatial light modulator and the sample to be detected and then is incident to the image sensor, both the image sensor and the spatial light modulator are connected with the computer, under the control of different phase information provided by the computer, the spatial light modulator is loaded with different random phase mask plates, every time a random phase mask plate is loaded, the image sensor is controlled to record a hologram for one time, multiple holograms are continuously and automatically obtained, and all reproductive images of the holograms are overlapped. The speckle noise of the reproductive images of the digital holography imaging system can be automatically reduced, and the all-solid digital holography imaging system capable of reducing the speckle noise can be used for imaging detection which is relatively high in requirements for instantaneity and distinguishability.

Description

technical field [0001] The invention discloses a digital holographic imaging system for realizing all-solid-state reduction of speckle noise based on a spatial light modulator, and belongs to the technical fields of optical diffraction imaging and digital holography. Background technique [0002] In the process of digital holographic recording, due to the "random" roughness of the sample surface relative to the wavelength of the illumination light, the use of coherent light illumination will introduce strong speckle noise, making it difficult to distinguish the details of the reconstructed image covered by speckle noise, which seriously affects the Imaging quality of digital holographic imaging system. A variety of methods to reduce speckle noise have been proposed. Based on the principle of wavelength-scanning interference holography, Kim et al. used ring dye lasers to reduce the speckle noise of synthetic images. However, this method needs to record object light, reference...

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Problems solved by technology

[0002] In the process of digital holographic recording, due to the "random" roughness of the sample surface relative to the wavelength of the illumination light, the use of coherent light illumination will introduce strong speckle noise, making it difficult to distinguish the details of the reconstructed image covered by speckle noise, which seriously affects the Imaging Quality of Digital Holographic Imaging System

A variety of methods to reduce speckle noise have been proposed. Based on the principle of wavelength-scanning interference holography, Kim et al. used ring dye lasers to reduce the speckle noise of synthetic images. However, this method needs to record object light, reference light and Holograms cannot be used for real-time observation; Rong et al obtained holograms in different polarization directions by manually rotating the polarizer to suppress speckle noise; Quan et al obtained multiple off-axis holograms by changing the angle at which the mirror irradiates the object, The average superimposition of multiple intensity reconstruction images can suppress speckle noise better, but this method requires manual and mechanical precise rotation of the mirror to obtain oblique illumination light

Kebbel et al. installed ground glass on the illumination optical path, and obtained multiple holograms with uncorrelated speckle patterns by rotating the ground glass. This method needs to mechanically move the ground glass in the experiment; it can be seen that in order to record multiple uncorrelated speckle patterns Most digital holograms require manual mechanical adjustment of optical components such as polarizers, mirrors, and frosted glass. However, the introduction of mechanical adjustments is often limited by factors such as the response speed, precision, and stability of the device itself, making the imaging speed not high. And the imaging system complex

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