Polarization-independent two-pump fiber optical parametric amplifier

Fiber-optical parametric amplifiers can be rendered polarization-independent by using two pumps with orthogonal polarization states. We have analytically investigated and experimentally demonstrated, for the first time to our knowledge, a flat-gain polarization-independent continuous-wave fiber optical parametric amplifier with 15 dB of gain over a 20-nm bandwidth, by using two orthogonal pumps.