Pulsed semiconductor lasers with higher optical strength of cavity output mirrors

Abstract

Asymmetric heterostructures with an ultrathick waveguide based on an AlGaAs/GaAs alloy system that allow lasing at a wavelength of 905 nm have been developed and fabricated by hydride metalorganic vapor-phase epitaxy. The internal optical loss and internal quantum efficiency of semiconductor lasers based on such structures were 0.7 cm-1 and 97%, respectively. It is shown that the highest output optical power of laser diodes with antireflecting (SiO2) and reflecting (Si/SiO2) coatings deposited on untreated Fabry-Perot cavity facets obtained by cleaving in an oxygen atmosphere reached 67 W in the pulsed mode and is limited by mirror damage. Treatment of Fabry-Perot cavity facets by etching in argon plasma and the formation of coatings with passivating and oxygen-blocking GaN and Si3N4 layers allowed an increase in the maximum output optical power to 120 W. Mirror damage was not observed at the attained output optical power.