SBIR Phase I: Development of Polycrystalline Laser Components Containing Gradients of Dopants

This Small Business Innovation Research (SBIR) Phase I project seeks to develop a method for the production of polycrystalline YAG laser gain media containing gradients of dopant in either linear or radial directions within the part. Such parts offer performance improvements for both output power and beam quality in diode pumped laser systems manufactured by commercial laser vendors. No commercial supplier of such components exists today. A technique based on deposition of thin layers of doped and undoped YAG nanopowder slurries stacked on top of one another to build up part thickness will be developed. Parts containing continuous (not step-wise) dopant gradients over distances up to one centimeter will be demonstrated, representing parts larger than those demonstrated in literature to date. Primary Phase I objectives include generation of uniform thickness layers to allow growth of uniform, thick parts, drying of slurry layers to produce crack free green bodies, and demonstration of high optical quality components containing prescribed doping profiles. Successful completion of the development will establish the capability to supply laser gain media containing dopant profiles to the commercial market, allowing substantial improvement in commercial diode pumped lasers with minimal modification of existing system architecture. The broader impact/commercial potential of this project stems primarily from the laser performance improvements that will be enabled by successful development of graded doping profiles in YAG based laser gain media. Graded doping profiles improve both maximum output power and beam quality of diode pumped solid state lasers. Such lasers are used in applications including laser cutting and welding, processing of electronics and photovoltaics, and laser sensing systems. Improvements made to these systems enable efficient domestic manufacturing in a cost competitive manner with respect to offshore manufacturing. Development of cutting edge manufacturing technologies is therefore key to re-establishing the US manufacturing base in the world market.