An optical modulator includes a semiconductor substrate and an optical waveguide portion disposed on the semiconductor substrate. A signal contact that extends alongside the optical waveguide portion is disposed on the semiconductor substrate. A first ground line is disposed on the semiconductor substrate spaced away from the signal contact by a first spacing. A second ground line is disposed on the semiconductor substrate spaced away from the signal contact by a second spacing opposite the first ground line. The first spacing is different from the second spacing.

Optical switch and modulator devices are described, usable for Terahertz data communication rates. The device comprising an optically transmissive substrate configured for propagating electromagnetic radiation therethrough and a metamaterial arrangement optically coupled to said substrate. The metamaterial arrangement comprises at least one layer of metamaterial particles optically coupled to at least some portion of said optically transmissive substrate, and at least one nanomesh layer made of at least one electrically conducting material placed over at least some portion of the at least one metamaterial layer. The at least one nanomesh layer configured to discharge electrons into the at least one metamaterial layer responsive to electromagnetic or electric signals applied to the metamaterial arrangement, and the at least one metamaterial layer configured to change from an optically opaque state into an optically transparent state upon receiving the discharged electrons, to thereby at least partially alter electromagnetic radiation passing through the substrate.

Optical modulators are described having a Mach-Zehnder interferometer and a pair of RF electrodes interfaced with the Mach-Zehnder interferometer in which the Mach-Zehnder interferometer comprises optical waveguides formed from semiconductor material. The optical modulator also comprises a ground plane spaced away in a distinct plane from transmission line electrodes formed from the association of the pair of RF electrodes interfaced with the Mach-Zehnder interferometer. The ground plane can be associated with a submount in which an optical chip comprising the Mach-Zehnder interferometer and the pair of RF electrodes is mounted on the submount with the two semiconductor optical waveguides are oriented toward the submount. Methods for forming the modulators are described.

An optical waveguide device including an optical waveguide substrate that has an electro-optic effect, is a crystal having anisotropy in thermal expansion rate, has a thickness set to 10 μm or lower, and includes an optical waveguide and a holding substrate that holds the optical waveguide substrate, the optical waveguide substrate and the holding substrate being joined to each other, in which the holding substrate is formed of a crystal having a lower dielectric constant than the optical waveguide substrate and having anisotropy in thermal expansion rate, and the optical waveguide substrate and the holding substrate are joined to each other such that differences in thermal expansion rate between the optical waveguide substrate and the holding substrate become small in different axial directions on a joint surface.

An optical waveguide element includes: a substrate on which an optical waveguide is formed; and an electrode that is formed on the substrate and controls a light wave propagating through the optical waveguide. The optical waveguide includes a protruding portion extending on the substrate, and the electrode includes a base layer made of Nb, and an upper layer formed on the base layer, the base layer being formed between the substrate and the upper layer. The occurrence of loss in propagating light is effectively suppressed due to the existence of the electrode that controls the propagating light in the optical waveguide element using the protruding optical waveguide

A semiconductor device include: a first bus waveguide; a first silicon ring optically coupled to the first bus waveguide; a backup silicon ring optically coupled to the first bus waveguide; a first heater and a second heater configured to heat the first silicon ring and the backup silicon ring, respectively; and a first switch, where the first switch is configured to electrically couple the first silicon ring to a first radio frequency (RF) circuit when the first switch is at a first switching position, and is configured to electrically couple the backup silicon ring to the first RF circuit when the first switch is at a second switching position.

A method of forming an electro-optical modulator including forming a lithium-niobate (LN) wafer including an optical waveguide situated within and proximate a first side of the LN wafer; bonding the LN wafer to a substrate such that the first side of the LN wafer faces the substrate; thinning the LN wafer; and forming coplanar transmission lines over and/or on a second side of the LN wafer, wherein the coplanar transmission lines extend parallel with and are laterally on either side of the optical waveguide.

A velocity mismatch between optical signals and microwave electrical signals in electro-optic devices, such as modulators, may be compensated by utilizing different lengths of bends in the optical waveguides as compared to the microwave electrodes to match the velocity of the microwave signal propagating along the coplanar waveguide to the velocity of the optical signal. To ensure the electrode bends do not affect the light in the optical waveguide bends, the electrode may have to be rerouted, e.g. above or below, the optical waveguide layer. To ensure that the pair of optical waveguides have the same optical length, a waveguide crossing may be used to cross the first waveguide through the second waveguide.

Disclosed is an electro-optic modulator. The electro-optic modulator includes a lower clad layer disposed on a substrate, an optical waveguide disposed on the lower clad layer, traveling-wave electrodes respectively disposed on both sides of the optical waveguide and each having a first distance to the optical waveguide, and ferroelectric blocks disposed between the traveling-wave electrodes and the lower clad layer and each having a second distance to the optical waveguide, which is less than the first distance.

An interferometer comprises a plurality of waveguide branches comprising a plurality of bus waveguides and a plurality of photonic resonators. A first waveguide branch of the plurality of waveguide branches comprises a first photonic resonator coupled to a first bus waveguide. The first photonic resonator is disposed to couple and circle a first portion of an optical beam at the first photonic resonator to generate a first phase shift of the first portion of the optical beam, where the first phase shift is the same as a second phase shift of a second photonic resonator coupled to a second bus waveguide.