The Army is interested in developing high power single mode photonic crystal based surface emitting lasers with the eventual goal of coherently combining them into a very high power single mode output beam delivering power levels suitable for HEL weapons, which will be a few hundreds of kWs in a single narrow divergence diffraction limited beam. Surface emitting lasers such as VCSELs or photonic crystal surface emitting lasers (PCSEL) are extremely reliable as they dont have facet damage problem and are configurationally better suited to be able to be combined into a coherent array. PCSEL device approach has made significant progress in recent years and there are single mode products in the market of around 200mW of output power with good mode quality from some vendors, but their efficiencies are not very good. We have an approach to increase the power level and efficiency with techniques that we propose in this SBIR. Our goal will be to increase the power level of single mode devices to >5W with high efficiency in the phase II of this SBIR. In phase I, we would develop the simulation tools and will design and fabricate some photonic crystal layers which can be integrated with the gain medium in phase II.
