Experimental Demonstration of Compact 16 channels-50 GHz Si3N4 Arrayed Waveguide Grating

Arrayed waveguide gratings (AWGs) are one of the key components for dense wavelength division multiplexing (DWDM) systems enabling wavelength(de)multiplexing and routing scaling to a large number of channels with graceful increases in optical losses. AWGs are widely used in telecommunications, datacom, optical sensing, optical spectroscopy, and many other applications. Such a wide range of applicability drives the need to realize AWGs on various material platforms and across various wavelength ranges [1–3]. But different platforms impose different design restrictions for AWGs. For instance silica AWGs have low index contrast which help to achieve low loss and crosstalk [1]. However, this low index contrast also requires the minimum bending radius to be relatively large and as a result, silica AWGs have typically large footprints. On the other hand, the high contrast silicon-on-insulator (SOI) waveguides allows very compact silicon-photonic AWGs [4] with tight bending, but this high contrast is also the reason for relatively high loss and high crosstalk. Therefore, the Si3N4/SiO2 waveguide platform with moderate index contrast [5] makes it an attractive alternative for low-loss, high-performance, and compact AWGs offering design fexibility and integrateability.