Compact Phase-Locked Fiber-Laser Array

"For directed energy applications such as the Airborne Laser (ABL) and other high energy laser systems, there still needs to be significant improvements in laser output power, brightness, stability, efficiency, as well as compactness and ruggedness.The proposed research will demonstrate the feasibility of a phase-locked array of fiber lasers using a proprietary technology developed in the Phase I project. The resulting system will provide a dramatic increase in power output and brightness and thus,the ability to deliver this power into a single, diffraction limited beam. It maintains a constant far-field pattern without complicated phase control of each laser element, providing very reliable and stable operation. It also readily increases inpower, brightness, efficiency, stability, and simplicity as the number of elements increases. Based on fiber lasers, it is highly efficient and uses a renewable source of energy.In this proposed effort, a 20 Watt breadboard system coherently combining seven (7) fiber lasers will be built and its phase locking properties demonstrated. Its operation will be studied under various perturbations such as misalignments, changes in theindividual optical-path-lengths, temperature changes, and vibrations. The feasibility of utilizing other laser types in the array will be examined."