title: Single-mode 2.65 µm InGaAsSb/AlInGaAsSb laterally coupled distributed-feedback diode lasers for atmospheric gas detection.
abstract: We demonstrate index-coupled distributed-feedback diode lasers at 2.65 µm that are capable of tuning across strong absorption lines of HDO and other isotopologues of H2O. The lasers employ InGaAsSb/AlInGaAsSb multi-quantum-well structures grown by molecular beam epitaxy on GaSb, and single-mode emission is generated using laterally coupled second-order Bragg gratings etched alongside narrow ridge waveguides. We verify near-critical coupling of the gratings by analyzing the modal characteristics of lasers of different length. With an emission facet anti-reflection coating, 2-mm-long lasers exhibit a typical current threshold of 150 mA at 20 °C and are capable of emitting more than 25 mW in a single longitudinal mode, which is significantly higher than the output power reported for loss-coupled distributed-feedback lasers operating at similar wavelengths.
authors: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
authors: Ryan M
authors: RM
authors: Briggs
authors: Clifford
authors: C
authors: Frez
authors: Mahmood
authors: M
authors: Bagheri
authors: Carl E
authors: CE
authors: Borgentun
authors: James A
authors: JA
authors: Gupta
authors: Mark F
authors: MF
authors: Witinski
authors: James G
authors: JG
authors: Anderson
authors: Siamak
authors: S
authors: Forouhar