Patent ID: 7457496

Claim:
A photonic integrated circuit chip comprising: a substrate; an input waveguide provided on the substrate and configured to supply a wavelength division multiplexed signal including a plurality of signal channels; a wavelength selective decombiner provided on the substrate and coupled to the input waveguide, the wavelength selective decombiner including a first elliptical grating and a second elliptical grating, the first elliptical grating having a first grating pitch and the second elliptical grating having a second grating pitch; and first and second photodetectors provided on the substrate, the first elliptical grating being configured to direct a first one of the plurality of signal channels to the first photodetector and the second elliptical grating being configured to direct a second one of the plurality of signal channels to the second photodetector,; wherein the first elliptical grating intersects the second elliptical grating at a plurality of open regions where the first and second elliptical gratings are discontinuous.