Optical Spectral Slicing Based Reconfigurable and Tunable Microwave Photonic Filter

Multiband microwave photonic filters (MPFs) are extensively required in emerging multifunction RF systems and high-performance radar systems. In this article, we present a reconfigurable and tunable multiband MPF. The flexible amplitude and phase controls of the multiband MPF can be achieved via optical spectral slicing by way of a programmable sampling function, i.e., varying the number of samples or the duty cycle of each sample. We verify that the number of uniform passbands can be adjusted (we obtain up to six passbands) and demonstrate a frequency tuning range of up to 432 MHz for a uniform triple-passband MPF. We also show a highly chirped triple-passband MPF with respective in-band chirps up to 30.0 ns/GHz, 42.1 ns/GHz, and 22.8 ns/GHz. These latter results illustrate a potential way to implement highly chirped multiband MPFs for high bandwidth signal processing applications.