Spectral Narrowing and Stabilization for Broad-Area Lasers via Modified Delivery Fiber

A proof-of-concept experiment for fiber-based broad-area laser stabilization is experimentally demonstrated using coupling optics and a 1-nm wide, 98% reflectivity fiber Bragg grating. The output spectrum of a 3-W, 100-μm wide, 2-mm long commercial broad-area laser was narrowed by more than 10× to 0.26-nm full-width half-max. In addition, the system showed 7%-13% enhanced output power. The system also shows potential for slow-axis beam quality improvement in the desired operating regime. A pump delivery fiber scheme is proposed for integration of the diode feedback into a pump system package for enhanced-brightness fiber pumping.