摘要
在理论分析优化的基础上,以BK7玻璃和石英为基底的高反射光学薄膜为样品,采用强度调制的连续激光作为激励光源,实验研究了表面热透镜(STL)技术和光热失调(PTDT)技术的信号幅值随激励光调制频率的变化关系,分析比较了这两种方法在测量光学薄膜吸收损耗方面的灵敏度。实验表明,光热失调技术具有构型优化简单、实验操作难度低和测量空间分辨率高等优点,对于具有较高反射率温度系数的高反射膜等样品,采用光热失调技术有利于提高薄膜吸收损耗测量的灵敏度。实验结果与理论分析基本一致。
Based on the theoretical configuration optimization, surface thermal lens （STL） and photothermal detuning（PTDT） experiments with a continuous wave modulated laser beam excitation are performed with highly reflective fihns coated on BK7 and fused silica substrates. The amplitudes of STL and PTDT signals as a function of the modulation frequency are experimentally measured. The sensitivities of STIr and PTDT in measuring the weak absorptance of optical coatings are compared. Compared with STL technique, the PTDT technique is experimentally simple and has a higher spatial resolution for absorption mapping of optical coatings, while maintaining the high measurement sensitivity. The experimental results sb.ow that for samples with a large temperature coefficient of reflectivity, the PTDT technique can obtain high measurement sensitivity. Agreement is obtained between the experimental results and the theoretical predictions.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2009年第2期467-471,共5页
Chinese Journal of Lasers
关键词
测最
微弱吸收
表面热透镜
光热失调
measurement
weak absorptance
surface thermal lens
photothermal detuning
