Optical time-domain reflectometry of discrete fiber Raman amplifiers

Optical time-domain reflectometry is proposed and demonstrated as a means to characterize the signal power evolution in discrete fiber Raman amplifiers. Up to 20-dB-gain amplifiers have been characterized comprising different fibers, under copropagating and counterpropagating signal-pump configurations, and under saturated and unsaturated conditions. The results demonstrate the flexibility of this simple and useful amplifier characterization technique. Simulations show good agreement with experimental results, and sustain the reliability of the technique.