Ultra-Compact Tuneable Notch Filter Using Silicon Photonic Crystal Ring Resonator

A novel ultra-compact photonic tuneable notch filter with large bandwidth, high extinction ratio, fast response, and flat stopband is modeled and designed. It consists of a silicon-based ring resonator with one-dimensional photonic crystal superimposed onto a ring portion. Engineering the defects into the photonic crystal section allows to achieve the equalization of the bottom band of the filter response. Large bandwidth (B = 10.43 GHz) and high extinction ratio (ER = 41 dB) have been attained with a frequency response of the first-order Butterworth filter type. Continuous and wide range tunability of the central frequency (15 GHz) has been obtained by using the carrier injection technique, together with fast reconfigurability (≈1 ns) and power consumption of 47 mW. The device footprint is as very small as about 150 μm 2 . This performance makes the proposed device suitable for several filtering applications, such as wireless networks (5G) and telecommunication reconfigurable payloads in Telecom and Space scenario, respectively.