The emission of a broad-area laser always contains several lateral modes (along the junction plane) even at low drive levels. To increase the discrimination against high-order lateral modes, we developed simple techniques for depositing a profiled thin layer of SiO on the output facet of a broad-area laser that has a 75-μm-wide injection current stripe. The profiled coating provided a nearly Gaussian reflectivity in the lateral direction (parallel to the junction plane). The resolved near-field spectra of the uncoated and coated lasers have been compared. The maximum output power in the single-lateral-mode regime was pushed to 25 mW with the profiled coating, compared with a corresponding power of less than 1 mW before deposition. Experimental results have confirmed the behavior predicted by our numerical simulations. This method is scalable to higher-power lasers.
© 1996 Optical Society of America
Damien Stryckman, Guy Rousseau, Marc D’Auteuil, and Nathalie McCarthy, "Improvement of the lateral-mode discrimination of broad-area diode lasers with a profiled reflectivity output facet," Appl. Opt. 35, 5955-5959 (1996)