Monolithic ridge-waveguide GaSbbased diode lasers were fabricated with a second-order, laterally etched Bragg grating to generate single-mode emission from InGaAsSb/AlGaAsSb multiquantum- well structures. In this design, the monolithic Type-I GaSb-based diode lasers use grating structures that exhibit low internal loss. The frequency-stable diode lasers meet the needs of high power (>50 mW) and narrow linewidth (≈100 kHz). These devices are strong candidates for replacement of the solidstate light sources. Furthermore, this design is not limited to this wavelength. By optimizing the quantum well, and the optical design, this innovation can adapt to any wavelength within the 2-to-3-μm spectral window with similar performance.

Commercial semiconductor distributed- feedback (DFB) lasers emitting at 2 μm are limited in power because of Auger recombination and other loss mechanisms at longer wavelengths on InP-based diode lasers. Additionally, GaSb-based LC-DFB (laterally-coupled distributed feedback) laser designs that incorporate metal gratings generate additional absorption loss in the laser cavity, limiting output power to approximately 10 mW. The lasers reported here exhibit low internal loss, making them suitable for high-power applications.

This work was done by Clifford F. Frez, Ryan M. Briggs, Mahmood Bagheri, Alexander Ksendzov, and Siamak Forouhar of Caltech for NASA’s Jet Propulsion Laboratory. For more information, contact This email address is being protected from spambots. You need JavaScript enabled to view it.. NPO-48769

Photonics Tech Briefs Magazine

This article first appeared in the January, 2014 issue of Photonics Tech Briefs Magazine.

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