An electrically-tunable microwave photonic filter based on polarization modulation

A multi-tap microwave photonic filter (MPF) with its center frequency tuned by a single parameter is proposed and demonstrated based on polarization modulation. By simply adjusting the amplitude of a sawtooth wave signal to a polarization modulator, the MPF is tuned with the shape and the free spectral range (FSR) unchanged. The proposed system has advantages in terms of simple operation, fast tunability and large bandwidth.