Patent ID: 7883914

Claim:
A method of fabricating a vertical cavity surface-emitting laser (VCSEL) structure containing a micro/nano-structured mode selective region, the method comprising the steps of: a. providing a substrate for holding the parts formed in the subsequent steps; b. forming a layer structure on the substrate, the layer structure comprising: (i) a bottom mirror consisting of two or more layers; (ii) a III-V based gain region formed above the bottom mirror, the gain region being adapted to generate light and to emit the generated light; (iii) a top mirror comprising two or more layers formed above the gain region so that the bottom and top mirrors form a laser cavity holding the gain region; (iv) a micro/nano-structured mode selective region positioned within the top mirror, the micro/nano-structured mode selective region comprising a light aperture, the dimensions of the micro/nano-structured mode selective region and the light aperture being adapted to at least partly control an efficiency of laser action in transverse electromagnetic modes of the cavity; wherein, the micro/nano-structured mode selective region being formed by: (i) forming a dielectric micro/nano-structured mode selective layer placed where the micro/nano-structured mode selective region is to be positioned; (ii) forming a masking layer on the dielectric micro/nano-structured mode selective layer, the masking layer comprising a masking pattern having a predetermined micro/nano-structured mode selective design/layout that corresponds to the micro/nano-structured mode selective region; (iii) etching, using an etch technique with the masking layer functioning as an etch mask, the predetermined micro/nano-structured mode selective design/layout into the dielectric micro/nano-structured mode selective layer to form the micro/nano-structured mode selective region; (iv) removing the masking layer; wherein layers of the top mirror above the dielectric micro/nano-structured mode selective layer are formed on the dielectric micro/nano-structured mode selective layer after the step of removing the masking layer; and wherein the etch technique has a first etch rate in the dielectric micro/nano-structured mode selective layer and a second etch rate in the layer on which the dielectric micro/nano-structured mode selective layer is formed, the first etch rate being higher than the second etch rate.