Abstract

Ultrafast all-optical wavelength conversion between widely-spaced channels is a significant function in optical telecommunications. Several techniques have been demonstrated for wavelength conversion from 1.3μm to 1.5μm, using nonlinear optical loop mirrors, semiconductor optical amplifiers, Raman resonant four-wave mixing process in birefringent optical fibers, or difference frequency generation in quadratic periodically poled waveguides. However, the maximum conversion efficiency was about -9 dB for all techniques, essentially limited by phase-matching constraints. In this paper, we address a new technique based on Raman-assisted three-wave mixing (RATWM) process in optical fibers [1]. This simple wide-range wavelength conversion technique does not require the fulfilment of stringent phase-matching, which permits flexible operating conditions. We present coupled mode calculations and numerical simulations of the nonlinear Schrödinger equation (NLSE) showing, in a simplified architecture involving purposely designed nonlinear dispersion-shifted fiber (DSF's), efficient wavelength conversion of a 1 31μm input signal to an output signal in the 1 5 μm spectral region.

© 2000 IEEE