Tunable single-frequency diode laser at wavelength λ=1.65 μm for methane concentration measurements

Abstract

This paper deals with the development of a novel single-frequency tunable diode laser with fiber-optic output for gas-analysis applications. The approach we propose is a convenient, simple and cheap solution for spectroscopy of single absorption lines of any gases having absorption bands in the optical fiber transparency window (0.7 μm/1.7 μm). The presence of fiber-optic output is an additional advantage for remote sensing applications. The laser operation is demonstrated as applied to R7 line of 2 ν 3 methane absorption band at λ=1.645 μm. The mode-hop-free tuning range of 35 GHz (1.2 cm −1) has been achieved.