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. © 2012 IEEE

HNLF-based photonic pattern recognition using remote transmitter

In this letter, a novel correlation technique based on matched filtering using four wave mixing with possible remote transmission is proposed. A pump wavelength, which is modulated by an input bit pattern is mixed with wavelength channels in a highly nonlinear fiber to generate idler wavelengths, which also carry the bit stream. Specific idler wavelengths are selected using software control of an optical processor to generate the reference template. These idlers are then 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. © 2014 IEEE

(IPC) A photonic correlation scheme using FWM with phase management to achieve optical subtraction

In this paper, a photonic correlation scheme that allows accumulation of negative signals is presented. The scheme uses four-wave mixing of pairs of signal and pump wavelengths, which are chosen such that they create idler wavelengths at a common wavelength. The total optical power at this target idler wavelength depends on the relative phase of each pump and signal wavelength. This concept has been applied to form a correlator where signal wavelengths are modulated by an input bit stream and mixed with pump wavelengths representing a reference bit pattern. This approach provides a correlation function with smaller unwanted noise peaks due to cancelation in the subtraction process. Simulation of the proposed correlation technique has been used to verify the concept using both intensity and phase modulation of the signal wavelengths. © 2009-2012 IEEE