Single-mode GaSb-based laterally coupled distributed-feedback laser for CO₂ gas detection

Abstract

We report on a GaSb-based laterally coupled distributed feedback (LC-DFB) laser with Cr gratings operating at 2004 nm for CO2 detection application. Being butterfly packaged with single-mode fiber pigtailed, the laser diode operates in the continuous-wave mode from -10 ℃ to 60 ℃, with the maximum output power of 2 mW and the maximum side-mode suppression ratio over 30 dB. Wavelength-modulated absorption spectroscopy of CO2 demonstrates the applicability of the LC-DFB laser for tunable diode laser absorption spectroscopy. Furthermore, the diode junction temperature, which has been measured using the wavelength shift method, exhibits a maximum value of 17 ℃ within the single-mode operation range.