Demonstration of Wavelength Selective Attenuator based on Second-order Micro-ring Resonator

We report the implementation of a two-channel wavelength selective attenuator based on second-order micro-ring resonators (MRRs). The attenuation of each channel is determined by the resonance wavelength deviation between the two cavities in the corresponding MRR, which is controlled by two independent driving voltages. We show continuous attenuation up to 15 dB for different channels with a spacing of 3.9 nm, with the O.5-dB bandwidth being above 125 GHz.