Abstract

MARTIN, J. A.  and  SANCHEZ, M.. Effect of GaN substrate thickness on the optical field of InGaN laser diodes. Rev. mex. fis. [online]. 2018, vol.64, n.3, pp.254-260. ISSN 0035-001X.

In this work the influence of GaN substrate thickness on the near and far-field patterns of InGaN lasers structures is numerically studied. In simulation a typical structure with an InGaN-MQW active region, GaN waveguide and AlxGa1−xN cladding layers is considered. A fluctuating behavior was obtained showing that for some values of the substrate thickness the near and far-field patterns can be optimized, while there are critical values that significantly reduce the confinement factor and widen the far field patterns. It is also shown that, replacing the n-GaN contact layer by a graded index (GRIN) AlxGa1−xN layer can help reduce the optical field leakage to substrate. Simulation results indicate that properly choosing the thickness of the substrate and using a GRIN n-AlxGa1−xN contact layer it is possible to improve both the confinement factor and far field patterns in nitride lasers.

Keywords : Optical field leakage; numerical simulation; InGaN laser diodes; GaN substrates.