2-Micron Wavelength Kilowatt Class High Energy Laser/Amplifier

High energy lasers (HELs) are in great demand for industrial material processing and directed energy weapon systems for defense and security. Compared to other laser platforms, fiber lasers have shown their excellence in producing high beam quality and high brightness HELs by taking advantages of their inherent attractive aspects including optical confinement in glass fibers, compactness, robust operation, easy thermal management, high power scalability, alignment-free operation, and low maintenance. Most kW-class HELs in development today are based on Yb3+-doped silica glass fiber lasers operating around 1 µm wavelength because of their high optical efficiency. But 1 µm lasers are neither eye-safe nor highly transparent in the atmosphere, which have severely restrained their in-field applications.  2 µm lasers are preferred over 1 mm and 1.5 µm lasers for long-range applications including direct energy laser weapon, LIDAR (LIght Detection And Ranging) and sensing systems, and direct optical communication because atmospheric scattering, atmospheric distortion, and thermal blooming are significantly reduced by operating at longer wavelengths.  NP Photonics is a pioneer in the design and fabrication of highly doped optical fibers and the development of high-performance fiber lasers at 2-micron. We propose to develop a scalable high-efficiency high-atmospheric-transparency HEL source based on spectrally combined Ho-doped germanate fiber lasers at 2.1-micron that are in-band pumped by Tm-doped fiber lasers at 1950 nm.