Low-Loss Flat-Top SOI CWDM Arrayed Waveguide Grating Router With Integrated Ge/Si Photodetectors

Abstract

We demonstrate a silicon-on-insulator (SOI)-based $4\times 4$ cyclic arrayed-waveguide grating router (AWGR) with integrated high-speed Ge/Si photodetector for coarse wavelength-division multiplexing (CWDM). By employing multimode output waveguides, the AWGR enables spectrally flattened passbands without additional insertion loss, while preserving a compact footprint and low crosstalk. The fabricated device exhibits insertion losses of 1.08–3.34 dB, 1-dB bandwidths exceeding 13 nm with 20 nm channel spacing and adjacent-channel crosstalk of <-18.8 dB. High-speed non-return-to-zero (NRZ) data routing experiments show clear open eye diagrams at data rates up to 32 Gbps, demonstrating the potential of the AWGR with multimode-outputs and integrated photodetectors for high-speed optical routing and reception applications.