Patent ID: 6915045
Filing Date: 2005-07-05
Classification: G02B

Abstract:
1. An optical waveguide type grating element for selectively reflecting each of signal channels in a reflection band out of a plurality of signal channels spaced at a channel spacing λ i , said optical waveguide type grating element comprising: an optical waveguide in which signal light including the plurality of signal channels propagates; and a grating which is an index modulation formed over a predetermined range of said optical waveguide, wherein the optical waveguide type grating element has a transmittance of −20 dB or less for each of the signal channels in the reflection band and has a reflectance of −20 dB or less for each of signal channels outside the reflection band, and wherein a deviation of a group delay time of each of the signal channels in the reflection band, which is caused by reflection in said grating, is 10 ps or less in a wavelength range of (λ