Electro-optical phase modulator having automatic resonant frequency adjusting function

Abstract

The invention discloses an electro-optical phase modulator, which comprises an electro-optical phase modulating crystal, a power extraction unit, a modulating power detection unit, a coherent power detection unit, a feedback signal generating unit, an electro-optical phase modulating crystal parallel resonant circuit, a main controller unit and an electro-optical phase modulator shielding shell, wherein the power extraction unit is used for extracting the power and a driving signal of an input modulating signal and the power of a coherent signal of a phase modulator reflected signal; the modulating power detection unit is used for converting the power of the extracted modulating signal into a voltage value; the coherent power detection unit is used for converting the extracted power of the coherent signal into a voltage value; the feedback signal generating unit is used of providing a feedback signal according to signals output by the modulating power detection unit and the coherent power detection unit; the main controller unit is used for acquiring and judging the feedback signal provided by the feedback signal generating unit, controlling the inductance value of the parallel resonant circuit according to a judgment result and automatically changing the resonant frequency point of the phase modulator till the resonant frequency point is matched with a modulating signal frequency; the resonant frequency of the phase modulator is always matched with a modulating signal frequency value output by a modulating power supply; and the electro-optical phase modulator shielding shell is used for protecting each component inside the electro-optical phase modulator and isolating external electromagnetic interference signals.

Description

technical field [0001] The invention relates to the field of photoelectric detection technology, in particular to an electro-optic phase modulator resonance frequency detection device and detection method, which are applied to the electro-optic phase modulator resonance frequency detection and calibration in a photoelectric detection system. Background technique [0002] In the field of weak photoelectric detection, due to the inevitable existence of a certain number of multi-order reflection ghost beams in the process of beam transmission in the optical system, the ghost beams generated after multiple reflections have the same phase and frequency as the main beam at the same point. The phase and frequency are exactly the same, which causes interference between the ghost beam and the main beam, resulting in a deviation between the detected optical signal and the ideal optical signal, resulting in a corresponding measurement error in the actual measurement result. In order to...

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Problems solved by technology

[0013] The present invention aims at the problem that the modulation efficiency decreases and even affects the modulation effect caused by the impedance mismatch between the modulation power supply of the electro-optic phaser and the electro-optic phase modulator during the application process of the existing electro-optical phase modulation technology. The existing adjustment device and method To solve the problem of time-consuming and labor-intensive problems, a design scheme and device for electro-optical phase modulator with the function of automatically adjusting the resonance frequency are proposed. And adjust the resonant frequency of the electro-optical phase modulator in real time according to the detection results to match the frequency of the output signal of the electro-optic phase modulation power supply, so as to achieve the purpose of improving the modulation efficiency. Moreover, through real-time online adjustment, it can avoid the need for system stop in the existing adjustment method Disadvantages that can only be adjusted after work and disassembly of the electro-optic phase modulator, improve system adjustment efficiency and use efficiency

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