Nonlinear spectral imaging system and method for underwater

Abstract

The present invention belongs to the optical technical field and relates to a nonlinear spectral imaging system and method for underwater. The system comprises a front optical system, a nonlinear crystal unit, a collimating lens, a first beam splitting element, a DMD or spatial light modulator, a second beam splitting element, an imaging mirror and a miniature photodetector which are sequentially arranged along an optical path; the system further comprises a feedback voltage adjustment system; laser emitted by a light source is reflected by a scene; the reflected laser passes through the front optical system, the nonlinear crystal unit, the collimating lens, the first beam splitting element, the DMD or spatial light modulator, the second beam splitting element, the imaging mirror and the miniature photodetector sequentially, so that the image information of the scene can be obtained; the image information is sent to the feedback voltage adjustment system; and the feedback voltage adjustment system adjusts the voltage of the nonlinear crystal unit according to the image information. With the nonlinear spectral imaging system and method for underwater of the invention adopted, the problem of the fuzziness and low signal-to-noise ratio of an optical imaging system in an underwater environment can be solved. The nonlinear spectral imaging system and method are used for detecting two-dimensional spatial information and spectral information of marine underwater targets and can obtain a high signal-to-noise ratio; and the working distance of the system is prolonged.

Description

technical field [0001] The invention belongs to the field of optical technology, and relates to a spectral imaging system and method, in particular to an underwater nonlinear spectral imaging system and method. Background technique [0002] Due to the attenuation of light by the water medium, forward and backward scattering of light when propagating in water, and the scattering effect of impurities in water, the spectral imaging system has the problems of poor image contrast, unclear image and low signal-to-noise ratio in water, so it is difficult to carry out long-distance imaging. The spectral imaging system can obtain two-dimensional spatial information and one-dimensional spectral information. Since the energy of the imaging spectrometer is divided into multiple spectral segments, the signal-to-noise ratio of each spectral segment is worse, and the system works at a closer distance. [0003] It is generally believed that noise is harmful. However, nonlinear systems base...

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Problems solved by technology

[0004] In order to solve the problem that the optical imaging system is not clear in water and the signal-to-noise ratio is low, resulting in a short detection distance, the present invention provides an underwater nonlinear spectral imaging system and method for detecting two Three-dimensional spatial information and spectral information, can obtain a higher signal-to-noise ratio, improve the system working distance

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