Characteristics of a semiconductor laser pumped brillouin amplifier with electronically controlled bandwidth

We demonstrate the operation of a semiconductor laser pumped fiber Brillouin amplifier. An optical gain of 5.5 dB/mW of pump power is obtained. The 15-MHz intrinsic bandwidth of the amplifier was extended more than one order of magnitude by adding frequency modulation to the pump laser. Bit-error-rate receiver sensitivity measurements with an in-line Brillouin amplifier demonstrate a 16-dB improvement in the system gain at 10 Mbit/s and a 8.5-dB improvement at 90 Mbit/s. Noise calculations show that the amplifier has an excess noise factor of 50-500 depending on the amplifier length and pump power.