光学学报, 2011, 31 (4): 0414003, 网络出版: 2011-04-01
宽调谐中红外差频激光及大气水汽浓度探测
A Widely Tunable Mid-Infrared Difference Frequency Generation Laser and Its Detection of Atmospheric Water
非线性光学 中红外 差频 二类相位匹配 AgGaS2晶体 水汽 nonlinear optics mid-infrared difference frequency generation type II phase matching AgGaS2 crystal water vapor
摘要
基于非线性差频技术,利用AgGaS2晶体通过二类相位匹配条件(e+o→e)产生了5~12.5 μm宽调谐差频激光(DFG)输出。抽运光源是一个再生激光放大系统,它由连续的Littrow结构光栅外腔半导体激光器和锥形半导体放大器组成,调谐范围为760~790 nm,最大输出功率可达800 mW(780 nm)。信号光源是连续可调谐钛宝石激光器,调谐范围为790~910 nm, 最大输出功率可达760 mW(806 nm)。差频激光在7.0 μm附近获得的最大输出功率为1.076 μW。基于产生的差频激光,采用直接吸收光谱方法测量了实验室大气中的水汽在7.0 μm附近(000→010)吸收带的吸收光谱。在19.0 cm的吸收光程条件下,依据记录的大气中水汽的吸收光谱获得了实验室大气中水汽的浓度。
Abstract
A widely tunable (5~12.5 μm) continuous wave mid-infrared laser based on difference frequency generation (DFG) in a AgGaS2 crystal with type II (e+o→e)phase matching is reported. The pump laser is a master oscillator power amplifier (MOPA) system which consists of a grating-tuned external-cavity diode laser in Littrow configuration and a tapered semiconductor amplifier, which is tunable from 760 to 790 nm with a maximum power of 800 mW(780 nm). The signal laser is a Tisapphire laser, which is tunable from 790 to 910 nm with a maximum power of 760 mW (806 nm). A maximum output power of 1.076 μW is obtained near 7.0 μm. Based on the difference frequency generation laser, the direct absorption spectrum of (000→010) band of water vapor near 7.0 μm in laboratory air is measured. Under the absorption optical path of 19.0 cm in open air, the concentration of water vapor in laboratory air is estimated from the recorded absorption spectrum.
汪六三, 曹振松, 王欢, 赵辉, 高伟, 袁怿谦, 陈卫东, 张为俊, 高晓明. 宽调谐中红外差频激光及大气水汽浓度探测[J]. 光学学报, 2011, 31(4): 0414003. Wang Liusan, Cao Zhensong, Wang Huan, Zhao Hui, Gao Wei, Yuan Yiqian, Chen Weidong, Zhang Weijun, Gao Xiaoming. A Widely Tunable Mid-Infrared Difference Frequency Generation Laser and Its Detection of Atmospheric Water[J]. Acta Optica Sinica, 2011, 31(4): 0414003.