Non-Uniform DFB-Surface-Etched Gratings for Enhanced Performance High Power, High Brightness Broad Area Lasers
Proc. SPIE 10086, Photonics West, San Francisco, USA, Jan 28 - Feb 02, 100860R (2017).
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Monolithic spectral stabilization is demonstrated in narrow-stripe broad-area lasers (NBA) with high power (5W), conversion efficiency (50%) and high brightness, by using optimized high-order surface-etched DFB gratings. However, surface etched gratings introduce a high index contrast into the semiconductor, leading to the scattering losses increasing rapidly with groove etch depth, limiting efficiency and yield. We therefore review progress in the exploitation of novel, non-uniform grating configurations for improved performance. Devices with non-uniform gratings whose groove etch depth decreases toward the front facet (apodized grating) are shown to operate with enhanced spectrally stable power (6W) compared to devices with uniform gratings.
Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
diode laser, broad area laser, low beam parameter product, lateral brightness, high efficiency.