Small-core As-Se fiber for Raman amplification

We have demonstrated Raman amplification in small-core As–Se fiber. More than 20-dB of gain was observed in a 1.1-m length of fiber pumped by a nanosecond pulse of $\sim 10.8‐\mathrm{W}$ peak power at $1.50 \mathit{\mu }\mathrm{m}$. The peak of the Raman gain occurred at a shift of $\sim 240 {\mathrm{cm}}^{-1}$. The Raman gain coefficient is estimated to be $\sim 2.3\times {10}^{-11} \mathrm{m}/\mathrm{W}$, which is more than 300 times greater than that of silica. The large Raman gain coefficient coupled with the large IR transparency window of these fibers shows promise for development of As–Se Raman fiber lasers and amplifiers in the near-, mid-, and long-IR spectral regions.