Three-dimensional wavelength-division multiplexing interconnects based on a low-loss SixNy arrayed waveguide grating.

Abstract

We fabricate three-dimensional wavelength-division multiplexing (3D-WDM) interconnects comprising three SixNy layers using a CMOS-compatible process. In these interconnects, the optical signals are coupled directly to a SixNy grating coupler in the middle SixNy layer and demultiplexed by a 1 × 4 SixNy array waveguide grating (AWG). The demultiplexed optical signals are interconnected from the middle SixNy layer to the bottom and top SixNy layers by four SiOxNy interlayer couplers. A low insertion loss and low crosstalk are achieved in the AWG. The coupling losses of the SiOxNy interlayer couplers and SixNy grating coupler are ∼1.52 dB and ∼4.2 dB, respectively.