摘要
频率调制(FM)光谱技术中由于激光偏振态变化产生的残余幅度调制(RAM)使其在微量气体检测中的应用受到极大的限制。理论上详细分析了这一过程产生的原因,获得了存在RAM时FM光谱线型的表达式,同时给出N.C.Wong和J.L.Hall(W-H)方案抑制RAM后的FM光谱线型表达式;在实验上通过对乙炔气体的测量获得了存在RAM时的光谱线型,同时采用W-H方案对RAM进行了抑制,并获得了优化的光谱线型;最后基于理论结果对实验线型进行了拟合,两者差值小于信号峰峰值的4%。
The residual amplitude modulation （RAM） induced by the polarized state changes of laser light in frequency modulation （FM） spectroscopy limits its application in the field of trace gas detection. The process is analyzed theoretically. The expression of the FM spectroscopic lineshape which contains the RAM is obtained. The expression of FM spectral lineshape is given when the RAM is restrained by N. C. Wong and J. L. Hall （W-H） method. The spectrum profile which contains the RAM is got by the measurement of the acetylene gases in the experiment. Then the W-H method is used to restrain the RAM and the optimized spectral lineshape is obtained. Finally, the results of the measured lineshape are fitted based on the theoretical method and the value difference between the two signals is less than 4 % compared with the signal peak value.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2012年第3期300-305,共6页
Acta Optica Sinica
基金
国家973计划(2012CB921603)
国家863计划(2009AA063006)
国家自然科学基金(61127017
61178009
10934004
60908019
60808009)
山西省青年科学基金(2010021003-3)资助课题
关键词
光谱学
频率调制光谱术
残余幅度调制
电光调制器
光谱线型
spectrosopy
frequency modulation spectroscopy
residual amplitude modulation
electro-opticmodulator
spectral lineshape
