Abstract

Currently all commercially available diode lasers are fabricated by cleaving dice from semiconductor wafers with the cleaved facets serving as the cavity mirrors. This practice is well suited to producing discrete devices but severely limits the degree to which these devices can be integrated into large scale monolithic systems. A method of producing laser mirrors, diffraction gratings, and other optical components directly in the surfaces of wafers is needed to integrate light sources with other optical elements and electronic devices. Experiments demonstrating the practicality of micromachining such structures with focused beams of ions from liquid metal sources are described. The micromachining was accomplished with a 20-keV Ga⁺ ion beam of 0.3-nA current focused to a 250-nm spot. Diode laser output mirrors were formed which show no increase in the lasing threshold and only a 20% decrease in external differential quantum efficiency when compared to cleaved mirror facets. Construction of coupled cavity single and multiple stripe diode lasers with the liquid metal focused-ion-beam micromachining technique is also described. Coupling grooves with submicron widths and depth-to-width aspect ratios of more than 10:1 have been achieved while maintaining the high optical quality of the groove walls.

© 1986 Optical Society of America