Grating stabilization design for high-power 980-nm semiconductor pump lasers

Abstract

Wavelength stabilization of high-power pump lasers for fiber amplifier applications involves complex interactions between the laser chip and the fiber Bragg grating (FBG). We present a comprehensive theoretical model for the window of operation in the coherence collapse (CC) regime while maintaining wavelength locking in 980-nm FBG-stabilized pumps. Experimental data from the development of a 500-mW grating stabilized pump verifies the theory. We also provide the first evidence that the critical feedback distance for CC operation of longer laser diode chips is sensitive to detuning.