High-Energy Short-Pulse Fiber Amplifier at Eye-Safe Wavelengths

Ultrashort Pulse (USP) lasers fall into two broad classes: bulk optical systems and fiber-based systems. The former generate meaningful pulse energies but have limited real-world utility due to their size and reliability issues. Alternatively, fiber lasers are extremely robust and easy to use but traditionally have not had the average output power and pulse energy necessary for some applications. Because small form factor and reliability are of paramount importance for widespread adoption of USP technology, Raydiance, in collaboration with OFS Labs, is pursuing technology to dramatically increase amplification of USP signals within a fiber-based system. In Phase I work, Raydiance and OFS demonstrated the feasibility of using rare earth doped higher order mode (HOM) fibers as a gain fiber for amplifying “eye safe” wavelength (1552 nm), chirped pulses. In Phase II, Raydiance and OFS propose to develop the components and gain fibers required to assemble an HOM fiber amplifier module. The module will then be integrated into a chirped pulse amplification (CPA) USP laser system for end to end system characterization. The Phase II Option plan includes the design, assembly and test of a packaged HOM fiber amplifier module for delivery to the Navy and integration into a laser system.