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AssigneeNippon Telegraph and Telephone Corporation
InventorsManabu Oguma, Akira Himeno, Kaname Jinguji, Tsutomu Kitoh, Yoshinori Hibino
Estimating the term…
An optical multi/demultiplexer is provided that has a wide passband and small crosstalk among its all channels. It includes first and second arrayed waveguide gratings and a 2×2 optical signal processor. The 2×2 optical signal processor includes first to fourth directional couplers, and first to third delay lines. The first to third delay lines have thin film heater phase shifters for correcting phase errors involved in fabrication. Utilizing the 2×2 optical signal processor having a transmission spectrum with a square profile having a wide passband and rejection band makes it possible for the optical multi/demultiplexer that combines the arrayed waveguide gratings with the waveguide type circulating filter (2×2 optical signal processor) to widen the extinction bandwidth of the adjacent channel.
An optical multi/demultiplexer including M arrayed waveguide gratings and a waveguide type circulating filter connected in cascade, each of the arrayed waveguide gratings having a same channel spacing and a center wavelength of a channel shifted by an amount of 1/M of the channel spacing, and the waveguide type circulating filter having M periodic output transmission spectra with a repetition period identical to the channel spacing, wherein said waveguide type circulating filter comprising:
Dependencies are inferred from the claim text.