We have demonstrated a photonic-assisted instantaneous microwave frequency measurement (IFM) system with add-drop micro-ring resonators (ORRs) on silicon-on-insulator (SOI) platform.

Two experiments have been set up with two rings which have different Q values. Two 25 μm radius ORRs with Q values of 3974 and 25833 are used to offer different measurement ranges and accuracies.

In the experiments the ORR with low Q value has a large measurement range of 0.5-35 GHz, and the other one with high Q value exhibits a high accuracy of 0.1 GHz in the frequency range of 0.1-5 GHz.