High-frequency-stabilization tunable narrow linewidth laser and use method thereof

Abstract

The invention discloses a high-frequency-stabilization tunable narrow linewidth laser, and the laser comprises a temperature control circuit, a linewidth laser and a drive circuit, wherein the temperature control circuit, the linewidth laser and the drive circuit are connected sequentially. The laser also comprises a first optical fiber coupler which is connected with an output end of the linewidth laser; a tunable microwave source module; a frequency shifter which is connected with the first optical fiber coupler; a second optical fiber coupler which is connected with an optical output end of the frequency shifter; an etalon which is connected with the second optical fiber coupler; a first power detection module and a second power detection module, which are respectively connected with the second optical fiber coupler and the etalon; a first amplification circuit and a second amplification circuit, which are respectively connected with the output ends of the first and second power detection modules; a first analog-digital conversion circuit and a second analog-digital conversion circuit, which are respectively connected with a first digital-analog conversion circuit and a second digital-analog conversion circuit; and a single-chip microcomputer which is connected with the output ends of the first and second analog-digital conversion circuits and the drive circuit. The laser can improve the frequency stability, reduces the linewidth, and achieves a function of wavelength continuous tuning.

Description

technical field [0001] The invention relates to the field of narrow-linewidth lasers, in particular to a narrow-linewidth laser with high frequency stability and tunable wavelength. The laser can be applied to the fields of radar and electronic countermeasures, coherent optical communication, precision interferometry and the like. Background technique [0002] Frequency-stabilized narrow-linewidth lasers are widely used in research fields such as radar and electronic countermeasures, coherent optical communications, precision interferometry, optical frequency standards, and laser gyroscopes. According to Schawlow-Tones' laser linewidth theory, the limit of laser linewidth caused by spontaneous emission is very small, but due to unstable factors such as thermal disturbance, electronic noise and mechanical vibration, the linewidth of lasers in practical applications is much larger than the theoretical line wide limit. If there is no adjustment and control, the frequency drift...

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Problems solved by technology

The external cavity tuning frequency stabilization method uses a Littrow structure to obtain a narrow linewidth single longitudinal mode through the optical feedback of the diffraction grating in the external cavity. The external cavity laser has a significant improvement in the linewidth of the general laser, but it is difficult to guarantee the long-term The stability is sensitive to mechanical changes and temperature fluctuations; the method of locking the optical frequency to the f-p cavity is mainly based on the phase modulation optical heterodyne frequency stabilization technology of the phase modulator, which has high sensitivity and signal-to-noise ratio. Moreover, it has a large adjustment range and good frequency stabilization effect, but the adjustment process is complicated and cumbersome, and the f-p cavity itself is easily affected by changes in the external environment such as temperature changes, mechanical vibrations, etc.; the optical frequency is locked to the atomic or molecular absorption line, The frequency locking sensitivity and long-term stability of the laser can be greatly improved. However, because the absorption lines are isolated, the commonly used methods such as the saturated absorption method simply lock the optical frequency to the absorption peak, and do not have continuous wavelength tunability.

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