Bent Directional Couplers for Broadband Silicon Photonic Interleavers

We experimentally demonstrate a broadband silicon photonic interleaver based on an add-drop resonator Mach-Zehnder interferometer (ADRMZI) with bent directional couplers. Utilizing wavelength-insensitive bent directional couplers, the measured crosstalk of the interleaver remains below -10 dB over a 90 nm bandwidth ranging from 1500 nm to 1590 nm, with the channel spacing of approximately 0.8 nm. The device footprint measures $400~\mu $ m $\times 280~\mu $ m. The proposed interleaver exhibits an average 1-dB bandwidth of 0.54 nm and an average shape factor (SF), defined as the ratio of the 1-dB bandwidth to the 10-dB bandwidth, of 0.54. This ADRMZI-based interleaver is well-suited for broadband wavelength division multiplexing applications.