Optical filtering method based on momentum matching of acousto-optic interaction

Abstract

The invention discloses an optical filtering method on the basis of acousto-optic interaction momentum matching. Relations between establishment of stable gratings and the diffraction efficiency are analyzed, and grating vector feature and momentum matching conditions are proved from coupled wave theories. Spatial filtering mechanisms start to be analyzed and researched from ultrasonic gratings by the aid of working mechanisms of acousto-optic deflectors, and accordingly the stable gratings can be established by the aid of obtained phase-determined signals to obtain high diffraction efficiency; the stable gratings cannot be established by phase-random signals, and the diffraction efficiency is lowered. The optical filtering method has the advantages that in-band noise can be effectively suppressed, the signals can be conditionally selected, the diffraction efficiency can be effectively controlled, and accordingly signal-to-noise ratios of systems can be obviously improved; in-band noise filtering effects of the acousto-optic deflectors can be verified by the aid of experiments and tests, merits of acousto-optic signal processing in the aspect of communication receiving system application can be sufficiently embodied, and development and application of acousto-optic devices in the future optical communication field can be promoted.

Description

technical field [0001] The invention relates to the technical field of optical filtering, in particular to an optical filtering method based on acousto-optic interaction momentum matching. Background technique [0002] In modern electronic warfare, it is necessary to track, monitor and analyze the frequency, amplitude, phase, angle of arrival, and time of arrival of spatially complex signals, capture all information of signal light in time, and solve the problem of communication receiving system information based on conventional electronic systems. Noise ratio improvement and sensitivity improvement are limited technical problems, so as to achieve effective interception of space electromagnetic wave signals in weak signal environments. [0003] Communication signal transmission is accompanied by noise accumulation. In order to effectively extract useful signals and suppress unwanted signals, different filters (such as low-pass filters, band-pass filters, etc.) are usually us...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is that the existing filtering method cannot suppress in-band noise, and an optical filtering method based on acousto-optic interaction momentum matching is provided

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