Nonlinear mixing based photonic correlator

We propose a novel correlation technique based on matched filtering using four wave mixing (FWM) in a length of highly nonlinear fiber (HNLF). A pump wavelength which is modulated by an input bit stream is mixed with wavelength channels to generate idler wavelengths which also carry the bit stream. The idler wavelengths are differentially delayed and summed at a photodetector to produce the required correlation function. This scheme has been experimentally demonstrated and the measured results verify the proposed concept. The technique allows remoting of the transmitter.