Methane Sensing with a Novel Micromachined. Single-Frequency Fabry?Perot Laser Diode. Emitting at 1331 nm.

Abstract

Spectroscopic-based gas sensing is demonstrated using micromachined single-frequency Fabry-Perot (FP) laser diodes emitting at 1.331 ?m with a side mode suppression ratio of greater than 24 dB over a significant emission wavelength tuning range. The utility of these novel mode controlled FP lasers for spectroscopic detection of gases is assessed by investigating the methane-absorption band in the 1.33 ?m region. By probing the narrow linewidth R2 rotational absorption line, we demonstrate a low gas detection limit of 28 ppm?m and confirm the suitability of micromachined lasers in such applications.