SBIR Phase I: Coilable Single Crystal Fibers of Doped YAG for High Power Laser Applications

This Small Business Innovation Research Phase I project will demonstrate the technical feasibility of the growth of coilable single-crystal fibers of doped yttrium aluminum garnet (YAG) of sufficient quality to improve the performance of high-power fiber lasers. Single crystal fibers are an intermediate between laser crystals and doped glass fibers. They can combine the advantages of both by guiding laser light and matching the efficiencies found in bulk crystals, making them ideal candidates for high-power laser and fiber laser applications. The technical challenge is to synthesize a cladded flexible fiber with a core of dopant (Er, Nd, Yb, etc.) that will exhibit good waveguiding properties. To achieve this, the Phase I technical objectives will be centered around the execution of various types of experiments to grow cladded YAG out of various feedstocks, followed by the characterization of each grown crystal and finally, the demonstration of lasing effects in cladded Nd:YAG. Successful completion of this project will culminate in the demonstration of flexible doped YAG fibers 200 mm in length, with doped cores 20 microns in diameter. The broader impact/commercial potential of this project is an improvement in the performance of fiber lasers for industrial applications. The worldwide market for lasers in 2011 was $7.5 billion. Technology areas which will be primarily impacted by this material innovation are material processing, medical, scientific/military, and instrumentation/sensors. The market for material processing lasers is $2.8 billion, and $1.2 billion for the other listed areas. The proposed work would enable laser manufacturers to commercialize higher-power, more efficient lasers. The market share of crystal fiber lasers is expected to grow to at least 10%, because of their performance capabilities. In the most conservative scenario, the cost of a crystal fiber component is estimated to be 2% of the selling price of the laser; therefore, the total addressable market for the crystal fibers themselves will be $2 million. By adding in associated gain modules and subsystems, the revenue potential of this product line increases to over $10 million. Further growth will be possible by enabling new applications with the unique properties of crystal fiber lasers.