Recent progress on arrayed-waveguide gratings for WDM applications

Wavelength filters with high channel numbers and a narrow channel spacing have become quite important for dense wavelength division multiplexing (DWDM) systems. Silica-based AWG, in particular, have many advantages in terms of extension to large scale devices, reproducibility, fabrication cost, and hybrid integration with semiconductor devices. In this paper, we describe recent progress on silica-based AWG for DWDM applications. The crosstalk in a 64-channel AWG with a 50 GHz channel spacing was about -4O dB. We also consider a temperature insensitive athermal AWG and a 16/spl times/16 AWG router.