REMOTE DETECTION OF METHANE WITH A 1.66-MU-M DIODE-LASER

被引:131
作者
UEHARA, K [1 ]
TAI, H [1 ]
机构
[1] TOKYO GAS CO LTD,INST TECHNOL,MINATO KU,TOKYO 105,JAPAN
来源
APPLIED OPTICS | 1992年 / 31卷 / 06期
关键词
REMOTE DETECTION; METHANE; DIODE LASER;
D O I
10.1364/AO.31.000809
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
High-sensitivity real-time remote detection of methane in air with a 1.66-mu-m distributed-feedback diode laser operating at room temperature is demonstrated by laboratory simulations. The laser current was modulated at a high frequency of approximately 5 MHz, and the laser-center frequency was locked onto a methane-absorption line. The laser light directed toward the probed region was received after one-way transmission or further reflection from a topographic target. The methane absorption was detected by the second-harmonic component in the optical-power variation. The minimum-detectable concentration-path-length product in the transmission scheme was 0.3 part in 10(6) m for a signal averaging time of 1.3 s. In the reflection scheme, the amount of methane could be measured from the ratio of the fundamental and second-harmonic signal intensities independently of the received power.
引用
收藏
页码:809 / 814
页数:6
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