Four-wave mixing between pump and signal in a distributed raman amplifier

Abstract

We observed experimentally four-wave mixing (FWM) between a 14xx-nm pump and a 15xx-nm signal in a forward-pumped distributed Raman amplifier (DRA) over 50 km of nonzero dispersion-shifted fiber with a zero dispersion wavelength of 1497 nm. The 100-mW pump Fabry-Pérot (FP) spectra centered at 1440, 1450, and 1460 nm are reproduced via FWM around the single-wavelength probe signal around 1558, 1548, and 1538 nm, respectively. The suppression of DRA gain by about 2-3 dB was experimentally observed with peak FWM at minimum phase mismatching between two 14xx-nm FP pump wavelengths and two 15xx-nm signal wavelengths. This DRA gain suppression, together with the reproduced pump FP spectrum at 15xx-nm signal band, may limit the usefulness of the forward-pumped DRA, generating spectrally nonuniform FWM-induced noise floors and crosstalk in wavelength-division-multiplexed fiber-optic transmission systems. Index Terms-Distributed Raman amplifier (DRA), four-wave mixing (FWM), nonzero dispersion-shifted fiber (NZ-DSF).

Non-degenerated Four-Wave Mixing Generated Power Ratio between Co-Propagated Pump Fabry–Perot Modes and Probe Signal in a Non-zero Dispersion Shifted Fiber

“…As a matter of fact, the FWM has the harmful effect to generate spectrally non-uniform FWM induced noise floors and crosstalk in wavelength division multiplexing (WDM) fiber optic transmission systems. 5,6) As a result, understanding the mechanisms of FWM and estimating the FWM efficiency are becoming very important for both the design and evaluation of WDM systems. Several methods for theoretical analysis of FWM in optical fiber have been reported.…”