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

Abstract

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 micron wide, 2 mm long commercial broad-area laser was narrowed by more than 10x to 0.26 nm full-width half-max. Additionally, 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.