Four-wave-mixing-based wavelength conversion of 40-Gb/s nonreturn-to-zero signal using 40-cm bismuth oxide nonlinear optical fiber

We experimentally demonstrate a compact and tunable four-wave-mixing-based wavelength converter using a Bi₂O₃-based nonlinear fiber (Bi-NLF). An only 40-cm-long Bi-NLF is used as a nonlinear optical medium for wavelength conversion of a 40-Gb/s nonreturn-to-zero (NRZ) signal with no additional stimulated Brillouin scattering (SBS) suppression scheme. The Bi-NLF used in this experiment has an extremely high SBS threshold owing to both its short length and relatively low Brillouin gain. The 40-cm Bi-NLF is fusion-spliced to standard single-mode fibers and its nonlinearity is measured to be ∼1100 W^-1·km^-1. Error-free wavelength conversion over a 10-nm bandwidth at a 40-Gb/s NRZ data rate is readily achieved with a pure continuous-wave pump.