Patent ID: 9335568
Filing Date: 2016-05-10
CPC Classification: G02F

Claim Text:
1. An optical modulator structure comprising: an RF waveguide having a first longitudinal axis; and at least one optical grating waveguide having a second longitudinal axis located within the RF waveguide, the first longitudinal axis being parallel with and substantially coincident with the second longitudinal axis such that, in use, an RF field propagating in the RF waveguide and an optical field propagating in the optical grating waveguide propagate in substantially parallel directions, the at least one optical grating waveguide having a grating adapted to provide a notch in a transmission spectrum for the optical field propagating in the optical grating waveguide and having an operating wavelength of the optical field propagating in the optical grating waveguide wherein the operating wavelength is selected to occur at a transition from a substantially maximum transmission to greater than minimum transmission in said optical grating waveguide, the optical field propagating, in use, in the optical grating waveguide having an optical group velocity at the operating wavelength; wherein the RF field propagating, in use, in the RF waveguide has a RF group velocity sufficiently equal to the optical group velocity to obtain a desired amount of amplitude modulation of the optical field propagating in the optical grating waveguide by said optical modulator.