On-Chip Reconfigurable Silicon Photonic Fabry-Perot Resonator

We propose and design an on-chip reconfigurable silicon photonic Fabry-Poret (FP) resonator. The proposed FP resonator mainly consists of a pair of Sagnac loop mirrors (SLMs) with tunable reflectivity and a low-loss multimode ridge waveguide, which is of great help to reducing the optical propagation loss and to improving the Q-factor of the FP resonator. To achieve flexible tunability, metal micro-heaters are placed on top of the multimode ridge waveguide and the directional couplers (DCs) of the SLMs. By tuning the direct current voltage applied to the micro-heaters, the resonance wavelength and the bandwidth of the proposed FP resonator can be flexibly tuned. As a demonstration, the chip is fabricated and characterized. Experimental results show that the resonance wavelength of the proposed FP resonator can be tuned within a range of 0.25 nm, and the bandwidth of the FP resonator can be tuned from 2.0 pm to 25.1 pm, corresponding to a tunable Q-factor from l7.8× 105 to l0.6× 105. The proposed FP resonator holds unique advantages including high Q-factor, flexible tunability, and compact footprint, which is potential to be widely used in microwave photonic signal processing and non-linear optical systems.