Index-antiguiding in narrow-ridge GaN-based laser diodes investigated by measurements of the current-dependent gain and index spectra and by self-consistent simulation

Luca Redaelli; Hans Wenzel; Joachim Piprek; Thomas Weig; Sven Einfeldt; Martin Martens; Gerrit Lükens; Ulrich T. Schwarz; Michael Kneissl

doi:10.1109/jqe.2015.2444662

arXiv · 1603.02528

Index-antiguiding in narrow-ridge GaN-based laser diodes investigated by measurements of the current-dependent gain and index spectra and by self-consistent simulation

Luca Redaelli·Hans Wenzel·Joachim Piprek·Thomas Weig·Sven Einfeldt·Martin Martens·Gerrit Lükens·Ulrich T. Schwarz·Michael Kneissl

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Abstract

The threshold current density of narrow (1.5 {\mu}m) ridge-waveguide InGaN multi-quantum-well laser diodes, as well as the shape of their lateral far-field patterns, strongly depend on the etch depth of the ridge waveguide. Both effects can be attributed to strong index-antiguiding. A value of the antiguiding factor R = 10 is experimentally determined near threshold by measurements of the current-dependent gain and refractive index spectra. The device performances are simulated self-consistently solving the Schr\"odinger-Poisson equations and the equations for charge transport and waveguiding. Assuming a carrier-induced index change which matches the experimentally determined antiguiding factor, both the measured high threshold current and the shape of the far-field pattern of lasers with shallow ridges can be reproduced theoretically.

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Luca Redaelli, Hans Wenzel, Joachim Piprek, Thomas Weig, Sven Einfeldt, Martin Martens, Gerrit Lükens, Ulrich T. Schwarz, Michael Kneissl. 2016-03-08. Index-antiguiding in narrow-ridge GaN-based laser diodes investigated by measurements of the current-dependent gain and index spectra and by self-consistent simulation. https://doi.org/10.1109/jqe.2015.2444662

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