New, Mid-IR Rare Earth Chalcogenide Glass Fiber Laser

This Phase I Small Business Innovative Research project will develop the most promising rare earth-doped chalcogenide glass materials for high-power mid-IR (2-5 um) emission, and demonstrate laser action with samples of cladding-pumped fiber drawn from two candidate materials. There has been and continues to be strong military interest in high power mid-IR lasers for optical countermeasures, ranging, remote sensing, target designation and free space and satellite communications. Cladding pumped fiber lasers are advantageous for high power operation because of their high efficiency and relative immunity from thermal effects. Furthermore, microstructured (photonic lattice) fibers have demonstrated strong potential for power scaling and immunity to fiber bending artifacts, thus enabling continual future development of improved high power, mid-IR fiber lasers. Phase I will develop a double-clad rare earth-doped chalcogenide glass synthesis technique for achieving mid-IR fiber laser operation, and will evaluate sample fiber material batches with two different rare earth-dopant materials for excitation efficiency and photon lifetime. Co-doping for improved electron energy transfer will be investigated. The fibers will be optically pumped to obtain mid-IR fiber laser emission. Phase II will further develop these materials, generate commercial fiber manufacturing processes, and demonstrate fiber materials for commercial and military laser products.