Photonic Microwave Filter with Single Passband combining Incoherent and Coherent Techniques

A method to eliminate the periodic spectral passbands of photonic incoherent multitap FIR filters based on adding a coherent optical filter is proposed and demonstrated. Experimental results show a single passband filter obtained from the combination of a three-tap FIR filter with a two-stage Lyot filter. This approach increases the range of operation of photonic microwave transversal filters to fully exploit the broadband nature of photonic technology.