Research on Measurement of Optical Fiber Raman Gain Coefficient

To design Fiber Raman Amplifier, Raman gain coefficient is important data. Stimulated Raman spectrum by backward pump measured at high pump is demodulated by spontaneous Raman spectrum measured at low pump which is a convenience method to measure Raman gain coefficient. Comparing to low-signal gain method, we can measure Raman gain coefficient stably and quickly. We measure two kinds of fibers, G652 and DCF. There are two gain peaks of G652 at 1523nm, 1533nm. The maximum gain peak is at 1523nm, and the gain coefficient is 3.7×10^-14m/W. The maximum gain of DCF is at 1523nm, and the value is 15.7×10^-14m/W. The measurement results are in good agreement with those by low-signal gain method.