All-Optical Tunable Multitap Microwave Photonic Filter Enabled by Fiber Optical Parametric Amplifier

We propose and experimentally demonstrate an all-optical tunable microwave photonic filter (MPF) based on single pump fiber-based optical parametric amplifier (OPA). The delay-line structure is achieved with a spool of dispersion-compensating fiber and a simple time-delay-compensating element. Owing to the idler generation during the OPA process, the frequency responses of 2-tap, 4-tap, and 8-tap MPFs are experimentally achieved by one, two, and four signal laser sources, respectively. Thus, ~50% reduction on the number of laser sources is accomplished. The tunability of the filter transfer function can be achieved through either continuously tuning the wavelength spacing of the signals or changing the total dispersion value.