A reconfigurable silicon photonic 4th-order filter for synthesizing butterworth, Chebyshev, and elliptic responses

We demonstrate a reconfigurable Si-photonic fourth-order all-pass filter-based topology to synthesize Butterworth, Chebyshev, and elliptic filter responses. Ring resonator drop port photodetectors provide electrical monitor information to tune the location of both the poles and zeros to dynamically set the desired filter configuration.