Design considerations for high-brightness diffractive broad-area lasers

Diffractive resonators have already been successfully applied to improve the transverse modal properties of solid-state lasers, gas lasers, external-cavity diode lasers, and diode-laser arrays. We discuss the possibility of designing monolithic diffractive broad-area lasers with a Gaussian fundamental mode and high modal discrimination. Using an empty resonator model, we demonstrate by numerical calculations that it is possible to achieve high-brightness diffractive broad-area waveguide lasers despite the large extent of the structures and fewer geometrical degrees of freedom. Owing to the diffraction of the fields inside the waveguide structures, the shape of the diffractive structures becomes important and needs to be considered in the design.