Fiber Pump Signal Combiner

This technology provides a method to combine a single mode signal beam and multiple multi-mode pump beams and efficiently couple them into the core and inner cladding of a double clad fiber respectively. Although devices currently exist to perform this function, the are limited in the maximum pump power they can withstand and the dimensions of double clad fibers they can accommodate. This invention represents an important breakthrough by enabling a uniform core diameter, and therefore efficient single-mode coupling throughout the device, for an arbitrary brightness-conserving transformation of the pump beams. This property does not exist in any currently-existing devices. Market Potential This invention can be used as commercial fiber lasers and amplifiers for defense and manufacturing applications. Defense applications include laser designation, ranging, LIDAR, and directed energy. Manufacturing applications include welding and cutting. Also will serve as a key component for next-generation high-power, lightweight laser systems. As such, the primary uses for the Air Force include unmanned aerial vehicles and satellite payloads. Benefits The main advantage and new feature of this laser is the use of etching to allow the pump cladding to be tapered while maintaining a constant or gradually-varying signal core diameter throughout the signal path. This allows high efficiency and reliability relative to existing technologies. This invention also eliminates contact between high-power laser radiation and polymer-based materials resulting in higher power handling capacity relative to existing technologies.