Abstract: All-optical wavelength converters based upon difference frequency generation (DFG) in optical chips with periodically poled materials are presented. Tunable continuous wave (CW) laser sources and various arrangements are made with the optical input signals in different ITU channels. In some arrangements the laser source(s) acts as the pump for the conversion of the input signals to different wavelengths. In other arrangement, the amplified input signals acts as a pump with the laser source in the role of the input signal. The net effect is that input signals are converted to different wavelengths. One-to-any, any-to-one, and any-to-any wavelength converters are described. Simultanenous conversation can also be preformed so that bands of signals may also be converted.

Abstract: A polarization-insensitive integrated wavelength converter system includes polarization-separating, polarization-rotating and wavelength-converter structures integrated into a monolithic optical structure. In one embodiment, a lithium niobate waveguide structure includes an integrated polarization separator which comprises two coupled Zinc-diffused and annealed-proton-exchanged waveguides, an electro-optic quarter-wave retarder, a mirror structure and a quasi-phasematching structure. In another embodiment, an electro-optic half-wave retarder and bent waveguide are used in place of the electro-optic quarter-wave retarder and mirror structure. In a further embodiment, an optical circulator is used in conjunction with the waveguide structure in order to discriminate between input and output optical signals.

Abstract: A WDM signal converter is provided. The signal converter is formed from a DFG and a separator, such as a WDM interleaver multiplexer/demultiplexer. The DFG receives first WDM channel signal(s) and converts into second WDM channel signal(s). The pump signal which energizes the conversion is set such that one-half of its frequency is set between, and more precisely, one-half, two WDM channels. This ensures that the second WDM signal is separated by an odd number of channels from the first WDM signal. The separator which receives the output from the DFG device, can then transmit the converted second WDM signal to one separator output port and transmit any first WDM signals, such as signals which have not been converted, to a second separator output port. In effect, the separator filters the output of the DFG.