Multi-species gas sensing using monolithic widely tuneable laser diodes

Abstract

Widely tuneable laser diodes operating in the 1520 ≤ λ ≤ 1570 nm are characterised and compared for use as sources for tuneable laser diode gas absorption spectroscopy. Three gases hydrogen cyanide, ammonia and acetylene with overlapping absorption features within the 50 nm tuning range of the devices were targeted employing wavelength modulation spectroscopy with second harmonic detection.