A method includes receiving light at a light input of an electro-optic modulator device. The method includes directing the light via the light input into optical waveguides in an optical layer of an electro-optic modulator of the electro-optic modulator device. The method includes receiving a signal at an electric input of the electro-optic modulator device. The electric input is associated with an input impedance. The method includes providing the signal to an electrode structure of the electro-optic modulator. The electrode structure generates an electrical field based on the signal. The electric field modulates light in the optical waveguides to produce modulated light based on the signal. The electrode structure includes a constant impedance section associated with a second impedance less than the input impedance. The method also includes providing the modulated light based on the signal from the optical layer to one or more output optic fibers.

To prevent deterioration in an extinction ratio due to asymmetry between a pair of optical waveguides.

An optical modulator has a Mach-Zehnder optical waveguide including mutually parallel first and second waveguides and a signal electrode for controlling the phase of light propagating in the Mach-Zehnder optical waveguide. The first and second waveguides have a first section in which the second waveguide has a line width smaller than that of the first waveguide and a second section in which the first waveguide has a line width smaller than that of the second waveguide. The first section and the second section are replaced with each other in curved parts.

To prevent deterioration in an extinction ratio due to asymmetry between a pair of optical waveguides.

An optical modulator has a Mach-Zehnder optical waveguide including mutually parallel first and second waveguides and a signal electrode for controlling the phase of light propagating in the Mach-Zehnder optical waveguide. The first and second waveguides have a first section in which the second waveguide has a line width smaller than that of the first waveguide and a second section in which the first waveguide has a line width smaller than that of the second waveguide. The first section and the second section are replaced with each other in curved parts.

There is provided an optical waveguide device including: a substrate; an optical waveguide formed on the substrate; and a working electrode that controls a light wave propagating through the optical waveguide, in which the working electrode includes a first base layer made of a first material, a first conductive layer on the first base layer, a second base layer made of a second material different from the first material, which is on the first conductive layer, and a second conductive layer on the second base layer, and an edge of the second base layer is covered with the second conductive layer, in a cross-section perpendicular to an extending direction of the optical waveguide.

A method and apparatus for efficiently modulating light includes forming a lithium niobate waveguide with a slab region and a ridge region to confine an optical mode traversing the optical modulator under the ridge region. An electro-optic polymer is formed on a top surface of the lithium niobate waveguide with the slab region and the ridge region having dimension sufficient to support an evanescent tail of the optical mode traversing the optical modulator under the ridge region during modulation. Light is applied to an input of the lithium niobate waveguide. A drive voltage is applied to the electro-optic polymer that modulates the light with the evanescent tail so that the mode expands into the electro-optic polymer material a length that provides a desired switching voltage-length product (V.sub.π*L).

A method and apparatus for efficiently modulating light includes forming a lithium niobate waveguide with a slab region and a ridge region to confine an optical mode traversing the optical modulator under the ridge region. An electro-optic polymer is formed on a top surface of the lithium niobate waveguide with the slab region and the ridge region having dimension sufficient to support an evanescent tail of the optical mode traversing the optical modulator under the ridge region during modulation. Light is applied to an input of the lithium niobate waveguide. A drive voltage is applied to the electro-optic polymer that modulates the light with the evanescent tail so that the mode expands into the electro-optic polymer material a length that provides a desired switching voltage-length product (V.sub.π*L).

A electronic method, includes receiving, by a graphene structure, a SPP mode of a particular frequency. The electronic method includes receiving, by the graphene structure, a driving microwave voltage. The electronic method includes generating, by the graphene structure, an entanglement between optical and voltage fields.

An optical device includes a silicon substrate, a waveguide formed of a thin film that is laminated on the silicon substrate and that is made of a perovskite oxide with a large electro-optic effect as compared to lithium niobate, and a cladding layer that covers the waveguide. Further, the optical device includes ground electrode that has a ground potential and a signal electrode that is arranged at a position facing the ground electrode and that applies driving voltage to the waveguide.

An optical device includes a silicon substrate, a waveguide formed of a thin film that is laminated on the silicon substrate and that is made of a perovskite oxide with a large electro-optic effect as compared to lithium niobate, and a cladding layer that covers the waveguide. Further, the optical device includes ground electrode that has a ground potential and a signal electrode that is arranged at a position facing the ground electrode and that applies driving voltage to the waveguide.

An optical coupling device is described herein. The optical coupling device comprises a first waveguide and a second waveguide that are formed on a common substrate, and a resonator that is positioned out of plane with the two waveguides. The resonator and waveguides are positioned such that light traveling in each of the waveguides evanescently couples to the resonator but not to the other of the waveguides. The optical coupling device can be used in connection with improving linewidth of a laser source for a lidar sensor. In another example, the optical coupling device can be used in connection with wavelength division multiplexing.