基于正交偏振双纵模的氦氖激光器纳米测尺系统

摘要

This paper presents He-Ne laser nanometer scale measurement system based on orthogonal polarization dual longitudinal mode.With inserted birefringence element,frequency splitting effect will occur inside He-Ne resonant cavity,turning the laser into dual frequency laser with adjustable frequency difference.By using effect of laser physics such as frequency splitting effect,mode competition effect and double longitudinal mode power tuning,and setting floating threshold,a new type of laser nanometer measurement ruler is proposed.The laser wavelength is applied as a ruler with traceability,leading to nanometer scale resolution without electrical subdivision.Experimental results of comparing with laser interferometer show that system optical resolution is 79 nm,measuring range is 15 mm,linearity is 5.4 ×10-5,and standard deviation is 380 nm.%提出一种基于正交偏振双纵模的氦氖激光器纳米测尺系统,将双折射元件插入He-Ne激光器谐振腔内产生频率分裂效应,使激光器变成了频差可调的双频激光器.运用频率分裂、模竞争、双纵模功率调谐等激光物理效应和设定浮动阈值,研制了新型的激光器纳米测尺.以激光波长为尺子,具有可溯源性,在没有任何电细分的条件下达到了纳米量级的分辨率,与激光干涉仪的比对实验表明,该系统的分辨率为79 nm,量程为15 mm,线性度为5.4×10-5,标准差为380 nm.