Wavelength Conversion by Difference-Frequency-Generation for Telecommunications Applications

Wavelength Division Multiplexing (WDM) networks make very effective utilization of the fiber bandwidth and offer flexible interconnections based on wavelength routing. In high capacity, dynamic WDM networks, blocking due to wavelength contention can be reduced by wavelength conversion. Wavelength conversion also allows distributed management of the network and facilitates scalability and modularity of the network. Numerous wavelength conversion techniques have been proposed and demonstrated to date. Wavelength conversion by Difference-Frequency-Generation (DFG) offers a number of unique characteristics not available in other techniques. DFG offers full transparency to signal formats and protocols; DFG accommodates analog and digital signals, ASK and FSK modulation schemes. DFG is also free from classical noise such as Amplitude-Spontaneous-Emission (ASE) and allows simultaneous multi-channel conversion with no significant crosstalk.