Programmable On-Chip Photonic Signal Processor Based on a Microdisk Resonator Array

A programmable on-chip photonic signal processor based on a silicon photonic microdisk resonator array is proposed and experimentally demonstrated. The processor has a two-dimensional mesh network structure with multiple input and multiple output ports. In each mesh cell, two identical thermally-tunable high-Q microdisk resonators (MDRs) are used for routing and processing the optical signal, and a low-loss waveguide crossing is employed at the waveguide intersection to enable low-crosstalk optical transmission. By programming the DC voltages applied to the MDRs, the processor can be reconfigured with diverse circuit topologies to perform multiple array signal processing functions. An 8 × 8 programmable signal processor is designed, fabricated and characterized. By controlling the DC voltages, an on-chip tunable optical delay line based on 8 MDRs cascaded in an all-pass filter configuration is experimentally demonstrated. Thanks to scalable mesh structure of the proposed processor, the entire device holds a promising potential for strong reconfigurability and parallel computing with low power consumption.