Open AccessSingle-mode 265 µm InGaAsSb/AlInGaAsSb laterally coupled distributed-feedback diode lasers for atmospheric gas detection
Author(s) -
Ryan M. Briggs,
Clifford Frez,
Mahmood Bagheri,
Carl Borgentun,
J. A. Gupta,
Mark F. Witinski,
James G. Anderson,
Siamak Forouhar
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.001317
Subject(s) - materials science , laser , optics , optoelectronics , semiconductor laser theory , tunable laser , quantum well , diode , molecular beam epitaxy , longitudinal mode , distributed bragg reflector , single mode optical fiber , wavelength , epitaxy , physics , layer (electronics) , composite material
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.