Double longitudinal mode laser offset frequency locking method and device based on thermoelectric cooler

Abstract

A double longitudinal mode laser offset frequency locking method and a device based on a thermoelectric cooler belong to the technical field of laser application. In the invention, the frequency of the output laser of a power balance type double longitudinal mode frequency stabilized laser A is taken as the reference frequency, and simultaneously the thermoelectric cooler is used for controlling the temperature to adjust the cavity length so that a fixed difference value is maintained between the frequency of the output laser of n>=1 double longitudinal mode lasers B1, B2, ..., Bn and the reference frequency, thus ensuring the output laser of the double longitudinal mode lasers B1, B2, ..., Bn to have uniform frequency value and the relative frequency stability and the frequency invariance to reach 10 and overcoming the shortcoming that the frequency invariance between the frequency stabilized lasers only reaches 10-10 because of inconsistency of the reference frequency in the traditional frequency stabilized lasers.

Description

technical field [0001] The invention belongs to the technical field of laser applications, in particular to a thermoelectric cooler-based dual-longitudinal-mode laser bias frequency locking method and a device thereof. Background technique [0002] In recent years, ultra-precision measurement and processing technologies represented by lithography machines and CNC machine tools have developed towards the direction of large-scale, high-precision, multi-space degrees of freedom simultaneous measurement, and put forward new requirements for laser interferometry systems, as shown in: On the one hand, the reduction of the processing line width requires the measurement uncertainty of the interferometric system to change from 10 -7 increase to 10 -8 , and then require the relative frequency stability of the laser light source to reach 10 -8 ; On the other hand, the large measurement scale and simultaneous measurement of multiple spatial degrees of freedom lead to a sharp increase ...

AI Technical Summary

Problems solved by technology

[0011] Aiming at the deficiencies of the existing laser frequency stabilization technology, the present invention proposes a dual longitudinal mode laser bias frequency locking method based on a thermoelectric cooler. Poor consistency leads to the problem of low comprehensive measurement accuracy, and provides a new type of laser light source with good frequency consistency, long life and direct application to industrial sites for the rapidly developing ultra-precision processing and measurement technology

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