Continuous-wave parametric amplification in bismuth-oxide fibers

We have investigated the suitability of highly-nonlinear bismuth-oxide fibers for obtaining net gain by continuous-wave one-pump parametric amplification. The high fiber attenuation (of the order of 2 dB/m) requires the use of fibers that are just a few meters long, and pump powers of the order of several watts. While these fibers have a relatively high SBS threshold compared to silica fibers, they still require substantial pump broadening for SBS suppression. The fibers have significant linear birefringence Δn=2×10-5Δn=2×10-5, which leads to the creation of narrow gain regions away from the pump. We have used this feature for successfully implementing a novel type of wavelength division multiplexing (WDM) demultiplexer with intrinsic gain.