Photonic Generation of Pulsed Microwave Signal Based on Phase Shifted Lyot Optical Filter

We propose and experimentally verify an approach to generate pulsed microwave signal with continuously tunable phase and discrete tuning in microwave frequency based on phase shifted Lyot optical filter in conjunction with wavelength-to-time mapping technology. The Lyot optical filter with the discretely tunable spectral spacing is realized by changing the state of polarization of the bidirectionally propagated optical signals. The frequency response of the filter is continuously tuned over a full free-spectral range (FSR) keeping its shape and FSR unchanged by simple adjusting the bias voltage of the phase modulator. The proposed approach could also obtain pulsed microwave frequency multiplication with a discretely tunable multiplication factor by simply cascading multiple Lyot optical filters in the form of series. The proposed scheme is theoretically analyzed and experimentally demonstrated.