BREAKING SYMMETRY IN THE BINARY PHASE-ONLY MATCHED-FILTER

A new means of breaking symmetry in binary phase only matched filters is reported. A randomly pixellated diffractive element is combined wit h a dynamic binary filter displayed on a ferroelectric liquid crystal spatial light modulator to produce a pseudo four-level phase matched f ilter. The four phase levels produced are sufficient to break inversio n symmetry without penalising the peak to noise ratio of the correlato r. A simulated annealing algorithm is used to generate dynamic section of the filter.