An apparatus includes a lithium niobate (LN) layer, and a planar electro-optical modulator having at least one hybrid optical core segment formed of a portion of the LN layer and an optical guiding rib. The optical guiding rib may be located in a top silicon layer of a silicon photonics (SiP) chip, to which a thin-film LN chip is flip-chip mounted, and may be coupled to optical waveguide cores in a first silicon core layer of the SiP chip. One or more drive electrodes are disposed between a substrate of the SiP chip and the LN layer. In some embodiments hybrid optical core segments may include silicon nitride core segments and may form an MZM configured to be differentially or dual-differentially driven.

An electronic device may include an antenna that conveys wireless signals at frequencies greater than 100 GHz. The antenna may include a radiating element coupled to a uni-travelling-carrier photodiode (UTC PD). An optical path may illuminate the UTC PD using a first optical local oscillator (LO) signal and a second optical LO signal. An optical phase shift may be applied to the first optical LO signal. A Mach-Zehnder modulator (MZM) may be interposed on the optical path. During signal transmission, the MZM may modulate wireless data onto the second optical LO signal while control circuitry applies a first bias voltage to the UTC PD. During signal reception, the control circuitry may apply a second bias voltage to the UTC PD that configures the UTC PD to convert received wireless signals into intermediate frequency signals and/or optical signals.

A structure for an optoelectronics platform and a method of fabricating a structure for an optoelectronics platform such as a Mach-Zehnder modulator or a waveguide. The method comprises the steps of providing a substrate, and depositing a BaTi03, BTO, film on a surface of the substrate and having a thickness suitable for single mode operation with one or more possible polarization configurations with optical confinement in the BTO film at a wavelength or wavelength range of operation; wherein the substrate is chosen to provide vertical refractive index confinement in a direction perpendicular to the surface of the substrate for the single mode operation optical confinement in the BTO film at the wavelength or wavelength range of operation.

An optical circuit of the present disclosure shares at least a part of an electrical path including phase variable means between neighboring optical interference circuits, or configures an electrical path so as to straddle neighboring optical interference circuits, thereby performing electrical or thermal feedback. The optical circuit includes a mechanism using the electrical or thermal feedback for cancelling components of thermal crosstalk from one optical interference circuit to another neighboring optical interference circuit. The optical circuit of the present disclosure has a resistor element that shares electrical paths including respective phase variable means between the neighboring optical interference circuits. The optical circuit changes the phase change amount by the phase variable means in the neighboring optical interference circuit, in such a way as to cancel the thermal crosstalk components by the resistor element.

An optical device includes an optical waveguide that is a rib type and that is formed of a thin film lithium niobate (LiNbO.sub.3: LN) substrate using a thin film LN crystal, and a buffer layer that is laminated on the optical waveguide. Furthermore, the optical device includes an electrode that is laminated on the buffer layer and that applies a voltage to the optical waveguide, and a gettering site that is disposed parallel to the optical waveguide and that traps an electric charge inside the optical waveguide.

The light modulator includes a substrate having a main surface including a first area, a second area, and a third area, a first III-V compound semiconductor layer of a first conductivity-type provided on the first area, a second III-V compound semiconductor layer of a first conductivity-type or a second conductivity-type provided on the second area, a core provided on the third area and including a group III-V compound semiconductor, and an electrode connected to the first III-V compound semiconductor layer. The first III-V compound semiconductor layer includes a first portion having a thickness smaller than a thickness of the core in a second direction orthogonal to the main surface and a second portion having a thickness larger than the thickness of the first portion in the second direction. The second portion is disposed between the first portion and the core.

The present invention provides devices, systems, and methods for producing bi-photons without the need for complex alignment or source design by the user. The invention provides a tunable source of high-brightness, high-visibility, bi-photons that can be configured for a number of applications.

Various embodiments include an electrical device comprising an antiferromagnetic topological insulator having a surface comprising a bulk domain wall configured to support a first type of 1D chiral channel, a surface step configured to support a second 1D chiral channel and intersecting the bulk domain wall to form thereat a quantum point junction.

Various embodiments of a monolithic transceiver are described, which may be fabricated on a semiconductor substrate. The monolithic transceiver includes a coherent receiver module (CRM), a coherent transmitter module (CTM), and a local oscillation splitter to feed a local oscillation to the CRM and the CTM with a tunable power ratio. The monolithic transceiver provides tunable responsivity by employing photodiodes for opto-electrical conversion. The monolithic transceiver also employs a polarization beam rotator-splitter (PBRS) and a polarization beam rotator-combiner (PBRC) for supporting modulation schemes including polarization multiplexed quadrature amplitude modulation (PM-QAM) and polarization multiplexed quadrature phase shift keying (PM-QPSK).

An optical device having a wavelength measurement section and an SMRS measurement section is disclosed. The wavelength measurement section includes a MZI, which includes first optical waveguides having a first optical path length difference. The wavelength measurement section also includes a second MZI, which includes second optical waveguides having a second optical path length difference. The second optical path length difference is greater than the first optical path length difference. The SMRS includes a filter adapted to suppress a primary laser mode of the second output optical signal and to pass a remaining portion of the second output signal to determine an SMRS based on an optical power of the main laser mode from the wavelength and power measurement stage, and an optical power of the remaining portion of the second output optical signal.