Seed injection single-frequency pulse laser based on tunable cavity length of electro-optical crystal

Abstract

The invention relates to a seed injection single-frequency pulse laser based on the tunable cavity length of an electro-optical crystal. By using an electro-optical effect of the electro-optical crystal, an external electric field is enabled to not change the polarization state of seed light but only change the phase thereof through adjusting the direction of the electro-optical crystal in a driven cavity. In each pump cycle, the electro-optical crystal driving power supply apples linear ramp voltage to the electro-optical crystal, the refractive index of the electro-optical crystal is changed, thereby changing the length of an optical cavity. A Q-adjusting switch is turned on after a photodiode detects a peak value of interference signals formed by the seed light passing through the driven cavity, thereby outputting single-frequency pulse laser. The laser has the characteristics of high working repetition frequency, high frequency stability, high interference resisting capacity, long service life and compact structure, not only can adapt to general requirements for a working environment, but also can adapt to airborne and satellite-borne requirements.

Description

technical field [0001] The invention relates to a single-frequency laser, in particular to a seed injection single-frequency pulse laser based on electro-optic crystal tuning cavity length. Background technique [0002] Single-frequency pulsed lasers are widely used in lidar, high-resolution laser spectroscopy, coherent communication, precision detection, gravitational wave detection and other fields. At present, the technical route commonly used to achieve single frequency in pulsed lasers is the seed injection method. The key to obtaining a highly reliable seed injection effect is that the frequency of the seed light matches the frequency of a certain longitudinal mode of the driven cavity. Therefore, a cavity length control system is needed to control the cavity length of the driven cavity in the seed injection laser. [0003] Commonly used cavity length control techniques include the establishment time minimization technique and the resonance detection technique. The ...

AI Technical Summary

Problems solved by technology

On the one hand, due to the mechanical oscillation and nonlinear effects of piezoelectric ceramics, the accuracy of the control and feedback of the cavity length of the driven cavity is limited, which in turn affects the frequency stability of the output laser.

On the other hand, if you want to further increase the working repetition frequency of the laser, the driving requirements for piezoelectric ceramics will increase, the response of piezoelectric ceramics will gradually deteriorate, and the service life will decrease, which will lead to poor system stability.

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