Epitaxially Re-Grown Photonic Crystal Surface Emitting Lasers

Photonic crystal surface emitting lasers (PCSELs) [1] offer the ultimate in control in semiconductor lasers. PCSELs have been shown to have high power scaling with area, high single-mode powers [2], large scale coherent emission, control of the beam shape and polarization with design of the photonic crystal geometry [3,4], as well as beam steering [5]. The photonic crystal, a two-dimensional variation in refractive index, provides feedback in multiple orthogonal directions. Wave propagating in various directions couple with one another and a 2D standing wave (cavity mode) is constructed over a broad area. These devices have previously been fabricated through wafer fusion or the formation of voids during the re-growth process. The manufacturability of such devices prompted the move towards epitaxially regrown structures that do not contain voids.