Perman & Green, LLP
Wavelength sorter and its application to planarized dynamic wavelength routing
 This invention provides methods and apparatus for achieving wavelength sorting multiplexer/demultiplexer and its application to the implementation of planarized dynamic wavelength routing. Using integrated arrayed-waveguide gratings, sorting can be achieved by two configurations. In the first configuration channel wavelengths are properly selected and launched into prearranged input waveguides of an arrayed-waveguide grating such that channels at the same wavelength and from all inputs will be demultiplexed and routed to adjacent outputs. Operated in the reverse direction, the same device becomes a sorting multiplexer. The second configuration achieves wavelength sorting by using the cascade of multiple arrayed-waveguide gratings and can also be operated as a demultiplexer or a multiplexer. Combined with space switches, the wavelength sorting multi/demultiplexer are utilized to implement the planarized channel-selective dynamic wavelength router. The function of wavelength sorting eliminates on-chip waveguide crossings and therefore reduces losses and crosstalks. The sorting demultiplexer and multiplexer can further be implemented with a single arrayed-waveguide grating. 
International Business Machines Corporation
G H
G02B H04Q
inventional inventional
Franklin Fuk-Kay Karen Weyl-Kuo
Tong Liu Wang