A control method based on a dual AOM cascade structure and an acousto-optic cascade module

Abstract

The invention discloses a control method and an acousto-optic cascade module based on a double-AOM cascade structure. The double-AOM cascade structure of the control method includes a first optical fiber acousto-optic modulator and a second optical fiber acousto-optic modulator. The control method obtains two radio frequency signals with consistent clocks by processing the system clock signal, and outputs the two radio frequency signals to the first and second optical fiber acousto-optic modulators respectively, so as to realize the first and second optical fiber acousto-optic modulation The clocks of the optical fiber acousto-optic modulators are unified, and the optical pulses generated by the first and second optical fiber acousto-optic modulators are delayed with the same external modulation signal to realize the delay synchronization of the two optical pulses; The vertical layered design of the module and the optical path module and the heat dissipation structure time realize the miniaturization of the acousto-optic cascade module. Therefore, this scheme can effectively realize the unification of the clock signals of the two optical fiber acousto-optic modulators and the synchronization of the delay of the optical pulse, and at the same time realize the miniaturization of the acousto-optic cascade module.

Description

technical field [0001] The invention relates to the technical field of acousto-optic optical fiber sensing, in particular to a control method based on a double AOM cascade structure and an acousto-optic cascade module. Background technique [0002] Doppler laser wind measurement radar, laser vibration measurement, distance measurement and distributed optical fiber sensing system have a series of excellent performance and characteristics such as high detection accuracy and non-contact measurement, and have broad application prospects and important application value. At present, systems at home and abroad are designed with separate photodetectors, optical fiber acousto-optic modulators, and some passive optical fiber devices, which have disadvantages such as large size, high power consumption, heavy weight, and poor versatility, which greatly limit the integration and application of the entire system. field. [0003] The fiber optic acousto-optic modulator (AOM) is the core ...

AI Technical Summary

Problems solved by technology

Among them, the single AOM method will have the following disadvantages in the use process: 1. The extinction ratio is insufficient, and the extinction ratio of a single AOM is generally only above 50dB; 2. The contradiction between the minimum optical pulse and the system processing capacity; In radar, laser vibration measurement, ranging and distributed optical fiber sensing systems, the optical pulse width determines the distance resolution. In order to obtain a smaller optical pulse width, it is necessary to increase the rise time of the AOM optical pulse, and the increase in the optical pulse time corresponds to the AOM The frequency must also be increased accordingly. The increase in AOM frequency will make the subsequent detector bandwidth and data acquisition card capabilities higher. And the ability of the acquisition card should be >400MHz

However, the dual AOM cascading method in the prior art is a simple patchwork between two AOMs, and each AOM has an independent driver, which will have the following disadvantages during use: 1. The two AOMs will be damaged due to inconsistent clock signals. 2) The optical pulses of the two AOMs need additional control delay to achieve synchronization; 3) The optical pulses output by the two AOMs have large jitter; 4) The volume of the two AOMs will increase

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