Lateral-mode discrimination in surface-emitting DBR lasers with cylindrical symmetry

A surface emitting DBR laser with cylindrical symmetry operating in a single lateral mode is investigated. The effective reflectivity resulting from the grating and the threshold gain of the different lateral modes are analyzed using the coupled-mode theory. The authors' results indicate that when a cavity is designed for operation in the odd lateral modes, all the even modes are effectively eliminated. A small perturbation is introduced into the complex dielectric constant of the active region to further suppress the unwanted lateral modes and produce single mode operation.