InGaN mini-laser diode arrays with cw output power of 500 mW

Abstract

One of the required features of nitride-based laser diodes is the possibility to obtain high output powers from devices, which is essential in e.g. RGB displays, lithography and high speed printing. This can be realized by means of multi emitter structures. We report on fabrication of a mini laser array, integrated on one laser chip and consisting of three emitters of the dimensions of 700 μm x 3 μm. The emitters structures was fabricated by MOVPE on top of the low defect density bulk GaN crystal obtained by ammonothermal method. We tested devices characterized by various pitches from 12 to 80 μm obtaining very similar results. Contrary to our previous study showing strong inter-emitter coupling we obtained independent emission from each stripe. This fact is a result of better vertical mode confinement and the suppression of substrate mode leakage. These latter effects were the reason for emitters coupling, as we reported previously. The new devices produced up to 500 mW of optical power, this value was limited by the thermal resistance of the whole package. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.