The implementation and application of a portable fiber-coupled trace-gas sensor for the detection of several trace gases, including CO2, CH4, and H2CO, are reported. This particular sensor is based on a cw fiber-amplified near-infrared (distributed Bragg reflector) diode laser and an external cavity diode laser that are frequency converted in a periodically poled lithium niobate crystal to the mid-IR spectroscopic fingerprint region (3.3–4.4 µm). A continuous absorption spectrum of CH4 and H2CO from 3.37 to 3.70 µm with a spectral resolution of 40 MHz (∼0.0013 cm-1) demonstrated the spectral performance that can be achieved by means of automated wavelength tuning and phase matching with stepper motor control. Autonomous long-term detection of ambient CO2 and CH4 over a 3- and 7-day period was also demonstrated.
© 2000 Optical Society of AmericaFull Article | PDF Article
OSA Recommended Articles
Michael Seiter and Markus W. Sigrist
Appl. Opt. 38(21) 4691-4698 (1999)
Thomas Töpfer, Konstantin P. Petrov, Yasuharu Mine, Dieter Jundt, Robert F. Curl, and Frank K. Tittel
Appl. Opt. 36(30) 8042-8049 (1997)
Appl. Opt. 57(15) 4039-4042 (2018)