Laser Scribing for Facet Fabrication of InGaN MQW Diode Lasers on Sapphire Substrates

In this letter, a novel method for the fabrication of high-quality facets for III-nitride lasers grown on
c
-plane sapphire substrates as well as on GaN substrates is presented. Based on a laser scribing process gain-guided laser diodes with smooth facets were fabricated, which showed threshold current densities of 6.5 kA/cm
²
at an emission wavelength of 405 nm under pulsed operation.