Effect of zero-dispersion wavelength variation on four-wave mixing in a fiber-loop mirror

Novel theoretical research on four-wave mixing (FWM) in a nonlinear optical fiber-loop mirror (NOLM) is presented. We assume that the NOLM is constructed from a polarization-maintaining dispersion-shifted fiber (PM DSF) with linear distribution of zero-dispersion wavelength (ZDW) through a 3 dB fiber coupler. The difference between this kind of NOLM and an ideal NOLM with one fixed ZDW is shown. It is found that the idler light generated by the FWM process in this NOLM can be partly transmitted, while the pump and signal lights can be reflected completely. The results show that the variation rate of the ZDW distribution along the optical fiber has a strong impact on the transmission profile of the idler light. (C) 2000 John Wiley & Sons, Inc.Engineering, Electrical & ElectronicOpticsSCI(E)EI0ARTICLE5310-3122