Tunable and Reconfigurable Photonic Signal Processor With Programmable All-Optical Complex Coefficients

A new all-optical microwave photonic filter structure that can realize arbitrary programmable complex coefficients, multiple taps, and shape-invariant frequency tuning over the full free-spectral range (FSR) range is presented. It is based on a new optical RF phase shifter achieved by using a programmable wavelength processor (PWP) comprising an array of liquid crystal on silicon pixels. It manipulates the amplitude and phase of optical spectral components, which enables both single-sideband modulation and arbitrary complex coefficient function to be obtained simply by versatile programming the PWP only, without changing the rest of the structure. Experimental results demonstrate reconfigurable and tunable shape-invariant multitap RF filters with wideband tuning range over the full FSR by software programming of the complex coefficients.