摘要
提出了一种连续波复合衰荡光腔(CRD)技术,可同时确定腔镜和待测镜高反射率,无需测量系统响应,提高了测量精度。以方波调制的连续激光耦合进衰荡腔,采用锁相方式探测衰荡信号一次谐波的振幅和相位。在数据处理中消除了系统响应的影响,由对应调制频率时直腔和折叠腔衰荡信号一次谐波的振幅比值和相位差值进行频域拟合,同时得到腔镜和待测平面镜的反射率。理论上推导了频域拟合函数。对100 cm共焦腔和110 cm稳定腔分别进行了直腔和折叠腔实验,最终确定腔镜反射率99.784%,待测平面镜反射率99.668%,测量精度达到10-5量级,与测量并消除系统响应后得到的反射率结果一致。
A simple cavity ring-down （CRD） technique based on an intensity-modulated continuous-wave （CW） diode laser is developed to determine simultaneously the reflectivities of the cavity mirror and the inserted planar mirror. The straight-and folded-cavity configurations with a same cavity length are established. Under both cavity configurations and with phase-locked technique, the amplitude and phase-shift of the first harmonic of the CRD signal are measured as a function of the modulation frequency covering an appropriate range. Effects of the system frequency response are eliminated in the data processing, and then the amplitude ratio and phase-shift difference between the two cavity configurations are fitted to an explicit theory to determine the reflectivities. The measurements are repeated with two cavity lengths, one of which is a 100 cm confocal cavity and the other a 110 cm stable cavity. The reflectivities of the cavity mirror and the inserted mirror are measured to be 99. 784% and 99. 668%, respectively, with an uncertainty in the order of 10^-5.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2007年第6期857-860,共4页
Chinese Journal of Lasers
关键词
测量
光腔衰荡
高反射率
折叠腔
连续激光
measurement
cavity ring-down
high reflectivity
folded cavity
continuous-wave laser
作者简介
龚元（1981-），男，湖北人，博士研究生，主要从事激光检测技术研究。E-mail：gongyuan3@hotmail．com
导师：李斌成（1966-），男，湖北人，研究员，博士生导师，主要从事光热技术和光学薄膜检测技术的研究。E-mail：bcli@ioe．ac．cn
