Hollow-Core Fibers for High-Energy Beam Delivery in CARS

This Phase I SBIR proposal addresses an Air Force need for enabling use of Coherent Anti-Stokes Raman Spectroscopy (CARS) for non-intrusive measurements of gas species and temperature in high enthalpy gas flows that are currently inaccessible or impractical with conventional CARS configurations. We propose to determine the feasibility of employing hollow core optical fibers to deliver pulses capable of generating CARS signals. This all-fiber-optical CARS system would enable the use of CARS in more hostile and restrictive environments. Lasers and other delicate equipment would be separated from a small measurement head that can be easily protected and manipulated in the vicinity of the test gas. We have identified several hollow core fiber types that appear to meet the necessary criteria and these will be evaluated as a part of the solution.