Raman fiber distributed feedback lasers

Abstract

We demonstrate fiber distributed feedback (DFB) lasers using Raman gain in two germanosilicate fibers. Our DFB cavities were $124\mathrm{mm}$ uniform fiber Bragg gratings with a π phase shift offset from the grating center. Our pump was at $1480\mathrm{nm}$ and the DFB lasers operated on a single longitudinal mode near $1584\mathrm{nm}$. In a commercial Raman gain fiber, the maximum output power, linewidth, and threshold were $150\mathrm{mW}$, $7.5\mathrm{MHz}$, and $39\mathrm{W}$, respectively. In a commercial highly nonlinear fiber, these figures improved to $350\mathrm{mW}$, $4\mathrm{MHz}$, and $4.3\mathrm{W}$, respectively. In both lasers, more than 75% of pump power was transmitted, allowing for the possibility of substantial amplification in subsequent Raman gain fiber.

© 2011 Optical Society of America