AWG-based devices for a WDM overlay PON

An overview of different approaches is given for overlaying a power-splitting PON in one wavelength band with a WDM comb in another wavelength band. Three versions of such a device for different broadcast wavelengths have been realized in silica technology. Eight channels of a WDM band around 1.55 mu m wavelength with 200 GHz spacing are overlaid on a 1 to 8 power split broadcast signal at either 1.31 pm or 1.50 pm wavelength. The key component is a 2-band MUX device that relies on a specially designed arrayed waveguide grating (AWG) integrated with a 1 to 8 power splitter ahead.