All-Fiber Components for Micro-Structured Fibers

We propose new concepts for developing components for high performance space based Lidar systems. While it is generally recognized that photonic crystal fiber technology can extend the performance range of fiber laser based sources these fibers are considered by many to be incompatible with complementary component technology such as fused couplers and pump combiners. Integration of these fibers into real systems for deployment either in space or terrestrial systems is hindered by the very structure which brings the advantage in effective area and nonlinearity mitigation. The problem is related to the air holes which provide guidance for both pump and signal. Our proposal centers not on developing sophisticated new component manufacturing techniques but rather on modifying the micro-structured gain fiber itself to retain the desirable advantages while eliminating the problems associated with component development. This can be achieved by use of only refractive index micro-structuring to create an all-solid structure with index control an order of magnitude better than direct deposition techniques. In the phase I program we will demonstrate an all solid micro-structured gain fiber with effective area >500µm2, as well as showing the feasibility of fabricating compatible tap couplers and pump combiners.