Control the transverse mode of vertical cavity surface emitting lasers by anti-reflection coating

Abstract

We have successfully developed a selective surface coating technique to control the modal behavior of the ion-implanted vertical cavity surface emitting laser. Using selective deposition of germanium coating by lift-off process, we could spatially control the threshold gain condition of the VCSEL to support the single transverse mode. The threshold current is 7 mA and single transverse mode operation is maintained up to 1 mW. The method is simple and nondestructive compared to other techniques.