Novel all optical serialised real time correlator using FWM and frequency to time mapping

A novel technique for obtaining the correlation of spectrally encoded information is presented. The information encoded in the spectrum of ultrafast optical pulses is mapped into time domain using dispersion and is then mixed with a spectrally engineered broadband pump using four wave mixing to create a narrow band idler. This idler could then be filtered and integrated using electronics. Unlike previous methods, all the stages, even template modulation, is carried out all optically. A correlation rate of 20MHz is demonstrated; but this is only limited by the repetition rate of the femtosecond fiber laser.