Method and device for locking laser frequency to optical frequency comb based on undersampling

Abstract

The invention discloses a method and a device for locking laser frequency to an optical frequency comb based on undersampling. The method comprises the steps of performing laser combination processing on to-be-stabilized frequency laser and laser of the optical frequency comb to obtain a detection signal, removing intermode self-beat signals between comb teeth of the optical frequency comb by a filter, performing undersampling acquisition on reserved beat signals into digital signals, reflecting or folding frequency spectra of the beat signals to a first nyquist region during an undersampling course, superimposing the beat signals to obtain a total beat signal, obtaining a phase error signal between the total beat signal and a reference sine signal by a phase locking amplifier, obtaining a frequency feedback control signal by digital PID (Proportion Integration Differentiation) operation, and adjusting output frequency of a to-be-stabilized frequency laser device by the frequency feedback control signal to realize offset frequency locking. The method and the device solve the problem of difficult increase of signal-to-noise ratios of the beat signals in a technology of locking a laser device to the optical frequency comb, improve the laser frequency stability, and can be widely applied to the field of laser precision metering.

Description

technical field [0001] The invention belongs to the technical field of laser frequency stabilization, in particular to a method and device for locking laser frequency to an optical frequency comb based on undersampling. Background technique [0002] Laser interferometry technology has the advantages of fast response speed, high measurement accuracy, strong anti-interference ability, and direct traceability to the definition of meters. Therefore, it is widely used in high-precision displacement measurement, ultra-precision processing and manufacturing, and instrument testing and calibration. The key to laser frequency stabilization technology is to select a stable reference frequency standard. Common laser frequency stabilization technologies can be divided into four categories: the first category is based on the center frequency of the gain curve and the center frequency of the Lamb sag, but the center frequency It is easily affected by conditions such as temperature and air...

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Problems solved by technology

[0004] In order to solve the problems existing in the background technology, the present invention discloses a method and device for locking the laser frequency to an optical frequency comb based on undersampling, which solves the problem that the signal-to-noise ratio of the beat signal is difficult to improve in the technology of laser frequency locking to the optical frequency comb question

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