Compact optical temporal differentiator based on silicon microring resonator.

We propose and experimentally demonstrate a temporal differentiator in optical field based on a silicon microring resonator with a radius of 40 microm. The microring resonator operates near the critical coupling region, and can take the first order derivative of the optical field. It features compact size thus is suitable for integration with silicon-on-insulator (SOI) based optical and electronic devices. The performance of this optical differentiator is tested using signals with typical shapes such as Gaussian, sinusoidal and square-like pulses at data rates of 10 Gb/s and 5 Gb/s.