Optical frequency mixers for WDM and TDM applications

摘要

All-optical functions such as wavelength conversion for WDM systems, gated mixing for TDM multiplexing and demultiplexing, spectral inversion for dispersion compensation, and optical switching have been widely studied in recent years. A number of techniques have been used to address various of these applications, including methods based on four-wave mixing in semiconductor optical amplifiers (SOA) and optical fibers, cross-gain and cross-phase modulation in SOAs, and the Kerr effect in a variety of media. Alternative methods based on three-wave mixing in χ~((2)) media, which otherwise could be applied to all of these functions with an attractive combination of low pump power, wide bandwidth, and negligible degradation of signal to noise ratio,[1] have not been widely exploited due to several technical issues. In this paper, we discuss resolution of these issues in three-wave-mixing and cascaded three-wave-mixing processes[2] based on periodically-poled lithium niobate (PPLN) waveguide devices, and their application to wavelength conversion, spectral inversion, and dispersion compensation by mid-span spectral inversion (MSSI) in a WDM transmission system.