LAUSR

We propose and experimentally demonstrate tunable microwave photonic filters (MPFs) with all-optical control, low-power consumption, ultra-high rejection ratios and large tuning ranges based on three cascaded silicon opto-mechanical microring resonators (MRRs). By injecting low pump powers, the nonlinear effects (mainly including the opto-mechanical effect) could be efficiently excited to manipulate the transmissions of the silicon device. Consequently, the bandwidths of the cascaded MRRs and the frequency interval between the optical carrier and the notch peak could be flexibly adjusted. Moreover, the extinction ratios of the cascaded MRRs could be largely increased when the three resonances are adjusted to be aligned, which contributes to achieving MPFs with high rejection ratios. In the experiment, by injecting a low-power of 3.4 mW, the central frequency and 3dB-bandwidth of the MPF could be tuned from 8.5 GHz to 38.5 GHz and from 8.8 GHz to 14.5 GHz, respectively. It should be noted that the MPF rejection ratios could realize beyond 60 dB. Furthermore, an MPF response with approximately equiripple stopband could be obtained.