Control method based on double-AOM cascade structure and acousto-optic cascade module

Abstract

The invention discloses a control method based on a double-AOM cascade structure and an acousto-optic cascade module. The double-AOM cascade structure of the control method comprises a first optical fiber acousto-optic modulator and a second optical fiber acousto-optic modulator, and the control method comprises the following steps: processing a system clock signal to obtain two paths of radio frequency signals with consistent clocks; respectively outputting the two paths of radio frequency signals output to a first optical fiber acousto-optic modulator and a second optical fiber acousto-opticmodulator so as to realize clock unification of the first optical fiber acousto-optic modulator and the second optical fiber acousto-optic modulator, and meanwhile, delaying optical pulses generatedby the first optical fiber acousto-optic modulator and the second optical fiber acousto-optic modulator with the same external modulation signal so as to realize delay synchronization of the two optical pulses. According to the acousto-optic cascade module, the miniaturization of the acousto-optic cascade module is realized through the vertical layered design of the circuit module and the light path module and the heat dissipation structure time. Therefore, according to the scheme, clock signal unification and optical pulse delay synchronization of the two optical fiber acousto-optic modulators can be effectively realized, and miniaturization of the acousto-optic cascade module is realized.

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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