Cancellation of fiber loss by semiconductor laser pumped brillouin amplification at 1.5 microns.

The propagation loss is cancelled, and 5 dB of net gain is obtained by Brillouin amplification in a 37.5 km long single mode optical fiber. A narrow linewidth external cavity semiconductor laser is used as the pump source and a gain of 4.3 dB/mW pump power is measured. The Brillouin linewidth is measured to be 150 MHz in contrast to previous measurements of ~20 MHz. The Brillouin Stokes shift was 11.3 GHz at 1.5 micron wavelength.