A silicon-on-insulator microring resonator filter with bent contradirectional couplers

We experimentally demonstrate a silicon-on-insulator microring resonator filter that uses bent contradirectional couplers to eliminate the filter's free spectral range. The filter's measured side-mode suppression is greater than 15 dB, the extinction ratio is ∼19 dB, and the 3-dB bandwidth is ∼23 GHz.