固体微片Nd∶YAG激光器的偏振跳变效应研究  

Research on polarization flipping effect of microchip Nd∶YAG laser

作　　者：陈浩楠 邓勇[1] 张书练[2] CHEN Haonan;DENG Yong;ZHANG Shulian(School of Mechanical Engineering,Nantong University,Nantong 226019,China;State Key Laboratory of Precision Measurement Technology and Instruments,Department of Precision Instruments,Tsinghua University,Beijing 100084,China)

机构地区：[1]南通大学机械工程学院,南通226019 [2]清华大学精密仪器系精密测试技术及仪器国家重点实验室,北京100084

出　　处：《激光技术》2023年第5期627-631,共5页Laser Technology

基　　金：国家自然科学基金资助项目(61775118)。

摘　　要：为了研究基于激光回馈的偏振跳变效应与相位延迟间的内在联系,采用微片Nd∶YAG激光器(中心波长1064 nm)为光源,回馈腔内置两个相对旋转的λ/4波片改变相位延迟,在调谐回馈腔长的过程中研究了激光器的光强输出和偏振态变化。结果表明,随着回馈腔内相位延迟增大,偏振跳变点的凹陷逐渐加深,两个偏振态的光强调制波形宽度趋于相同;当回馈腔中相位延迟为90°时,两正交偏振态在一个强度调制周期内持续时间相同,每一次偏振跳变对应回馈腔长改变λ/4。此不同相位延迟下偏振跳变点的变化规律,为1064 nm波长下的波片相位延迟测量提供了潜在方法,同时相位延迟对激光器输出光强曲线的整形、为激光回馈条纹(自混合干涉条纹)的光学细分提供了依据。In order to study the intrinsic relationship between the polarization flipping effect and the phase retardation based on laser feedback,the output intensity and polarization state of the laser were observed during the tuning of the feedback cavity length by using a microchip Nd∶YAG laser(central wavelength of 1064 nm)as the light source and two relative rotatingλ/4 wave-plates in the feedback cavity to change the phase retardation.The results indicate that,with the increase of phase retardation in the feedback cavity,the indentation depth of the polarization flipping position gradually deepens,and the width of the light intensity modulation waveform of the two polarization states tends to be the same.When the phase retardation in the feedback cavity is 90°,the duration of two orthogonal polarization states to be the same in an intensity modulation period,and each polarization flipping corresponds to a change ofλ/4 feedback cavity length.The variation of the characteristic point of polarization flipping caused by different phase retardation provides a potential measuring method for phase retardation of waveplate at 1064 nm wavelength.Meanwhile,the change of phase retardation shapes the output light intensity waveform of laser,which provides a basis for optical subdivision of laser feedback fringe(self-mixing interference fringe).

关 键 词：激光光学 偏振跳变 微片激光器 外腔双折射回馈 

分 类 号：TN248.1[电子电信—物理电子学]