An optical circuit is designed with demultiplexing and optical detection
functionality with minimal crosstalk. An Nth order harmonic generation
device is positioned before the demultiplexer to either convert the
frequency or down convert the wavelength of the demultiplexed light wave
by N-times. Upconverting the multiplexed signal at the receiver station is
performed by either simultaneously upconverting N-times to create N times
the original spacing between each optical channel or by upconverting the
frequency of one optical channel at a time.
