Demonstration of 1.3-μm Raman Fiber Amplifier Gain of 25 dB at a Pumping Power of 300 mW

Abstract

We present the first demonstration of 1.3-μm Raman fiber amplifier gain of 25 dB at a pumping power of only 300 mW using a low-loss high-Ge-doped silica fiber. A gain coefficient value of about 0.1 dB/mW has been achieved. The application of silica fiber fabricated by well-established technology and containing 18 mol% GeO2 with reduced losses of 1.1 dB/km at the wavelength of 1.31 μm has entailed the achievement of high gain efficiency, which turns out to be comparable to that of the Pr-doped fluoride fiber amplifier. Numerical analysis has shown that the Raman net gain may be higher than 30 dB at a pumping power of 300 mW and the gain coefficient may reach 0.15 dB/mW at 1.309 μm. The obtained results allow us to consider the Raman amplifier as a possible practical alternative to the Pr-doped fluoride fiber amplifier.