Novel Techniques to Combine Optical Radiation from Fiber Lasers

Aculight proposes a scalable approach to passive phasing of fiber laser arrays to meet the requirements of high power, high spatial brightness sources for high energy laser (HEL) applications. The system design is scalable to up to 100 kW output with high brightness. The proposed approach will establish generalized scaling rules enabling the laser designer to confidently predict the degree to which brightness can be maintained as the array becomes larger. In the phase I we will demonstrate up to 20W output with near diffraction limited output by passive mode-selection from an arrayed structure and study the physics of self organization. We will also investigate higher mode-volume multi-moded fibers as alternative building blocks for later phases of the program and as a means for establishing generalized brightness enhancing scaling rules for different array elements and architectures. In the phase II we will deliver a prototype laser system based on the phase I breadboard but upgraded in pump power to enable 500W of output power. We will also quantify the brightness achievable from the next level array structure.