Patent ID: 8718413
Filing Date: 2014-05-06
Classification: G02F,H01S

Abstract:
1. An optical modulation apparatus comprising: a substrate; a first optical waveguide and a second optical waveguide formed at an interval on the substrate; an electrode along at least one of the first optical waveguide and the second optical waveguide; and a power source coupled to the electrode to apply a voltage to at least one of the first optical waveguide and the second optical waveguide, wherein at least one of the first optical waveguide and the second optical waveguide includes a plurality of diffraction grating regions where light having a wavelength λ is reflected, and a phase shift region where a phase of the light is shifted by an amount in a range of 0 to λ/2, each of the plurality of diffraction grating regions including a high refractive index region and a low refractive index region having a refractive index that is lower than that of the high refractive index region, the phase shift region including a plurality of shift regions, the diffraction grating regions being provided on both sides of one of the plurality of shift regions, wherein a number of cycles of diffraction gratings in each of a plurality of first diffraction grating regions of the plurality of diffraction grating regions is substantially twice a number of cycles of diffraction gratings in each of a plurality of second diffraction grating regions of the plurality of diffraction grating regions, one of the plurality of second diffraction grating regions being positioned on a far side of an incidence portion and the other of the plurality of second diffraction grating regions being positioned on a far side of an outputting portion, a first shift region of the plurality of shift regions being positioned immediately next to the one of the plurality of second diffraction grating regions and a second shift region of the plurality of shift regions being positioned immediately next to the other of the plurality of second diffraction grating regions, the remaining plurality of shift regions and the plurality of first diffraction grating regions being arranged immediately alternative to each other between the first shift region and the second shift region.