Investigation of the techniques deployed in spectrum slicing for microwave photonic filters

This paper discusses the various techniques for spectrum slicing of a broadband source used in microwave photonic filters. Use of Michelson interferometer, fiber Bragg gratings (FBG), Fabry-Perot filter, arrayed waveguide gratings (AWG) and other components for finer and clearer spectrum slicing are investigated. Each technique is different from the other, on the basis of tunability, maximum number of spectral slices, free spectral range (FSR), band pass central frequency and sidelobe suppression level. Advantages of a technique over its preceding ones have been discussed in terms of tunability, reconfigurability, sidelobe suppression level and cost. Demerits of the above techniques lead to suggestions in improvement in the filter performances. Optical CAD tools for the design of spectrum sliced microwave photonic filters are also proposed.