Laser intensity noise suppression device for Nd:YVO4 laser

Abstract

The invention belongs to the technical field of lasers, relates to a laser intensity noise suppression technology, and particularly provides a laser intensity noise suppression device for an Nd:YVO4 laser. The device provides feedback signals and applies feedback signals to the two ends of an electro-optical crystal of the Nd:YVO4 laser, voltage applied to the electro-optical crystal is effectively adjusted, the transmissivity of the electro-optical crystal is further adjusted, the loss of a laser resonant cavity is further adjusted, and the intensity of laser output by the laser is adjusted. Through the electro-optical modulation, the intensity modulation of the laser output by the laser is realized, so that the laser intensity noise is suppressed, and the problem that the gain adjustment is limited by the bandwidth of an LD pump laser in the prior art is effectively solved. In conclusion, the response speed of electro-optical modulation is high, broadband feedback control can be formed, the suppression effect of laser intensity noise can be improved, and the modulation bandwidth is remarkably improved.

Description

technical field [0001] The invention belongs to the technical field of lasers, relates to laser intensity noise suppression technology, and specifically provides a method for Nd:YVO 4 Laser intensity noise suppression device for intracavity modulation of lasers. Background technique [0002] Semiconductor lasers have the advantages of tunability, compact structure, and good coherence, and have a wide range of application scenarios; however, the intensity noise of semiconductor lasers is relatively strong, resulting in unstable output power of the laser. Intensity noise represents the fluctuation of the output laser light intensity, which can be represented by the optical power per unit area. At present, there are many methods to suppress intensity noise, mainly including injection locking, photoelectric feedback, mode cleaner, etc.; such as the literature "BelfiJ, Galli I, Giusfredi G, et al. the phase-noise-to-amplitude-noise conversion [J]. Journal of the Optical Society...

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Problems solved by technology

[0003] The photoelectric feedback method is to convert a part of the output laser light into a current using a photodiode, and then input it to the input current of the semiconductor laser (pump source) through a driving circuit. The AC part of the feedback signal is coupled to the semiconductor laser without affecting the DC drive current of the semiconductor laser, and the laser intensity noise is suppressed by feedback modulating the drive current of the semiconductor laser; however, the entire feedback loop needs to have a relatively large gain. It is necessary to realize appropriate phase lead compensation near the relaxation oscillation peak to the high frequency region to prevent the feedback loop from self-oscillation, and the gain of this negative feedback modulation is limited by the bandwidth of the pump laser, and it is difficult to obtain a wide range Intensity Noise Suppression

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