基于1392nm高灵敏度积分腔的痕量水汽测量

发布时间：2018-01-22 12:34

本文关键词： 光谱学痕量检测吸收光谱离轴积分吸收水分含量　出处：《激光与光电子学进展》2017年06期 　论文类型：期刊论文

【摘要】：介绍了基于分布式反馈(DFB)激光器作为光源的离轴积分腔吸收光谱装置,并将其应用于高纯氮气(N_2)以及标准甲烷(CH_4)中水汽含量的测量。将中心波长为1392nm的出射光,通过准直器耦合到长度为60cm,由两片高反射率镜片组成的谐振腔内,透过腔的信号经过聚焦后由光电探测器接收。利用CH_4标准气体在不同压强下对腔镜的反射率进行校准。当腔内的压强为1.599kPa时,镜片的反射率可达到0.99843±0.00003。选取H2O在7189.344cm~(-1)和7185.597cm~(-1)处的谱线分别对N_2和CH_4中的水汽进行测量。在200s采集时间内,最佳噪声等效吸收系数分别为1.65×10~(-8) cm~(-1)和3.75×10~(-8)cm~(-1),对应的体积分数探测极限分别为2.28×10~(-6)和4×10~(-6)。采用本波段最强的吸收谱线(7181.155cm~(-1)),探测极限可以分别提高24倍和19倍左右,达到95×10~(-9)和210×10~(-9)。若采用反射率更高的镜片,结合最强的吸收谱线,则该系统水汽体积分数的探测极限可以达到10~(-12)量级。
[Abstract]:An off-axis integrated cavity absorption spectrometer based on distributed feedback DFB laser as a light source is introduced. It has been applied to the measurement of water vapor content in high purity nitrogen (C _ 2N _ 2) and standard Ch _ 4). The central wavelength of 1392 nm emission light is coupled to the length of 60cm by collimator. The resonator consists of two high reflectivity lenses. The signal through the cavity is received by the photodetector after focusing. The reflectivity of the mirror is calibrated by using CH_4 standard gas at different pressures. When the pressure in the cavity is 1.599kPa. The reflectivity of the lens can reach 0.99843 卤0.00003.The H _ 2O is selected at 7189.344 cm ~ (-1) and 7185.597 cm ~ (-1). The water vapor in Ns _ 2 and CH_4 was measured respectively. The optimum noise equivalent absorption coefficients are 1.65 脳 10 ~ (-8) cm ~ (-1) and 3.75 脳 10 ~ (10) ~ (-8) cm ~ (-1) respectively. The corresponding detection limits of volume fraction are 2.28 脳 10 ~ (-6) and 4 脳 10 ~ (-1) respectively. The strongest absorption line in this band is 7181.155 cm ~ (-1) ~ (-1). The detection limit can be increased by 24 and 19 times, respectively, to 95 脳 10 ~ (-9) and 210 脳 10 ~ (10) ~ (-9). If a lens with higher reflectivity is used, the strongest absorption line can be combined. The detection limit of water vapor volume fraction of the system can reach 10 ~ 12).
【作者单位】：南昌航空大学江西省光电检测技术工程实验室;南昌航空大学无损检测与光电传感技术及应用国家地方联合工程实验室;
【基金】：国家自然科学基金(41265011) 江西省研究生创新专项资金(YC2015-S330) 人社部留学人员科技活动项目择优资助项目
【分类号】：O433.1;TN248
【正文快照】： 063001-1the system can be up to the level of 10-12 if the mirrors with a higher reflectivity and the strongest absorption lineare used.高新技术密集产业,特别是半导体行业,需要对水汽含量进行准确测量和控制[1]。例如,半导体生产过程需要大量的N2、Ar或He作为保护

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