Modeling of surface grating-loaded VCSEL with slowing light

Abstract

We propose single-mode vertical cavity surface-emitting lasers (VCSEL) based on the surface grating with various cavity lengths ranging from 10 μm to 1 cm. We present the modeling of surface grating-loaded VCSEL based on the coupled-mode theory with slowing light. Thanks to the low effective index caused by the slow-wave propagation, a shallow surface grating of a few tens nm provides large optical feedback. A narrow stop band in the surface grating-loaded VCSEL waveguide appears because of the large waveguide dispersion of slow-waves. The numerical results on coupling coefficient, mode selectivity and threshold gain are given for single-mode, long-cavity and short-cavity grating-loaded VCSELs with different grating parameters. A wide range of grating coupling strength enables a short cavity of 10 μm and a long cavity of 1 cm with a single-mode operation. The proposed VCSEL structure may open up new VCSEL platforms for low-power consumption and high-power applications.