Temperature dependence of gas-detection sensitivity of InGaAsSb/AlGaAsSb distributed feedback lasers at 2396 nm

The HF gas detection sensitivity of GaSb-based distributed feedback lasers was studied in order to evaluate the potential use of operating temperature to control the laser output power in field applications. Measurements were made in the 2f wavelength modulation spectroscopy mode to monitor a prominent HF absorption feature at 2396 nm. An Allan variance analysis indicates that the best sensitivity is obtained when a larger thermoelectric current is applied to maintain temperature control by actively heating or cooling the laser. The reduced detection sensitivity for a setpoint near the ambient laser operating temperature is similar to that obtained without active temperature control.