High power surface grating slow-light VCSEL

Abstract

We report on a novel high power vertical cavity surface emitting laser (VCSEL) with high order shallow surface grating, which enables a single mode operation even for 6 mm long devices. A high single mode power of over 3 W is obtained under pulsed operations for a 6 mm long oxide aperture. A fan-shape beam with sub-degree narrow divergence is obtained up to high injection currents of 5 A. Thanks to the low effective index of slow-light modes in a VCSEL structure, the grating pitch is over 2.5 μm, which can be made by using a standard photo-lithography. The simple fabrication process and potentials of high power and high beam quality could make the proposed laser to be a good candidate for 3D optical sensing and imaging applications.