Acousto-optic deflector with phase-controlled transducer array

Abstract

The invention particularly relates to an acousto-optic deflector with a phase-controlled transducer array. A plurality of transducer electrodes are arranged on a piezoelectric layer on the surface of acousto-optic crystals, and are driven by an independent radio frequency (RF) signal source; the phase difference between RF signals is adjustable; and the acousto-optic deflector works in an abnormal Bragg diffraction mode and can increase the bandwidth by adopting slow-mode incident light and tangent conditions. The range of the tracking angle desired for ultrasonic tracking can be reduced by adopting the tangent conditions of abnormal Bragg diffraction, thereby further increasing length of a single transducer electrode, improving acousto-optic interaction length, or reducing the number of desired transducer electrodes, and reducing system complexity. The acousto-optic deflector can be widely used in the application fields of microscopic imaging, laser display and record system, laser processing, laser measurement and control, and so on.

Description

technical field [0001] The invention belongs to the technical field of laser scanning, and in particular relates to an acousto-optic deflector with a phase-controlled transducer array. Background technique [0002] The acousto-optic deflector is a diffraction device that deflects the light beam by using the acousto-optic coupling effect. Its principle is to generate ultrasonic waves by the ultrasonic piezoelectric transducer bonded on the surface of the acousto-optic material. A volume grating is formed in it to deflect the beam. Its addressing speed reaches the order of microseconds, and its application is mainly limited by its small scanning range, while the scanning range of the acousto-optic deflector is determined by formula (1) [0003] Δθ = λΔf v - - - ( 1 ) [0004] Among them, λ is the wavelength of light in vacuum, Δf is t...

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Problems solved by technology

However, in "Generalized phased array Bragg interaction in anisotropic crystals", Eddie H. Young at el, Optical Technology for Microwave Applications V, 1991 pointed out that when using the first-level tracking method to track the Bragg angle near the extreme point, the tracking error is large , the effect is not as good as the case of fast mode incidence

[0010] Another implementation of the phase-controlled transducer array uses multiple independent RF drive sources to drive the transducer array, which can achieve complete tracking with zero tracking error. This implementation method is rarely used due to high system complexity. is adopted, but the tracking effect is significantly better than the first-level tracking method

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