An optical switch is provided which is capable of driving control by the same FPGA and the same driving circuit configuration, and hence is capable of driving at a high speed and a low consumption power. The optical switch of the present disclosure is a 1×N optical switch having a structure in which with respect to an optical switch, a driving circuit of the optical switch is integrated in the vicinity of a control electrode of the optical switch. The optical switch includes a plurality of 2×2 optical switches and N optical gates. Different bias voltages (V.sub.b) are set between the optical switches and the optical gates, and a driver for the 2×2 optical switch of the driving circuit and a driver for the optical gate are of the same circuit form

An optical modulator includes: an optical waveguide element including an optical waveguide formed on a substrate and a signal electrode for controlling a light wave propagating through the optical waveguide; a drive circuit for outputting two high-frequency signals; and two terminating resistors for respectively terminating outputs of the two high-frequency signals from the drive circuit. The output of one of the high-frequency signals of the drive circuit propagates through the signal electrode of the optical waveguide element and is terminated by a first terminating resistor which is one of the terminating resistors. The output of the other of the high-frequency signals of the drive circuit is terminated by a second terminating resistor which is the other of the terminating resistors. A resistance value of the second terminating resistor is greater than a resistance value of the first terminating resistor.

An optical module includes: a housing having a first face and a second face parallel to the first face; a first block fixed to the first face of the housing by a first adhesive; an integrated circuit (IC) fixed to the first block by a second adhesive having a thickness larger than a thickness of the first adhesive; a thermoelectric cooler (TEC) fixed to the second face of the housing; an optical circuit element fixed to the TEC; and an interconnection board mounted on the IC and the optical circuit element, the interconnection board being configured to electrically couple the IC to the optical circuit element. The first block is sandwiched between the housing and the IC. The TEC is sandwiched between the housing and the optical circuit element.

According to one embodiment, an optical module includes: a lid having a first face and a second face, the lid including a bump, a wiring, and a through via; an optical circuit element; a first integrated circuit (IC); a first block bonded to the first IC by a first adhesive; a temperature control element bonded to the optical circuit element; and a housing having an opening and a third face provided inside the opening, the housing being configured to house the first IC, the optical circuit element, the first block, and the temperature control element, the third face being bonded to the first block and the temperature control element by a second adhesive, the housing being hermetically sealed with the lid.

An optical interferometer device is provided including a waveguide interferometer. The waveguide interferometer includes first and second waveguide arms in a waveguide plane, each waveguide arm including a n-type region and a p-type region forming a junction. The n-type region and the p-type region of the second waveguide arm are translationally symmetric with respect to the n-type region and the p-type region, respectively, of the first waveguide arm in the waveguide plane.

A Dual Parallel (DP)-Inphase/Quadrature (I/Q) Mach-Zehnder Modulator (MZM) bias controller configured to generate a pair of orthogonal dither signals; multiply the pair of dither signals to create a second order orthogonal dither signal; and lock an Inphase (I) I MZM of a DP-I/Q MZM to a value of a corresponding I component of a transmission signal by applying the pair of orthogonal dither signal to a Quadrature (Q) MZM and a Phase (P) MZM of the DP-I/Q MZM; applying an I bias signal to the I MZM of the DP-I/Q MZM; detecting an output of the DP-I/Q MZM; and determining an I error signal in the output of the I MZM of the DP-I/Q MZM based on the product of second order dither signal and the output of the DP-I/Q MZM.

High bandwidth (e.g., > 100 GHz) modulators and methods of fabricating such are provided. An optical modulator comprises transmission lines configured to provide a respective radio frequency signal to a respective plurality of segmented capacitive loading electrodes; pluralities of segmented capacitive loading electrodes in electrical communication with a respective one of the transmission lines and in electrical communication with an interface layer of a semiconductor waveguide structure; and the semiconductor waveguide structure. The semiconductor waveguide structure is configured to modulate an optical signal propagating therethrough based at least in part on the respective radio frequency signal. The semiconductor waveguide structure comprises the interface layer, which (a) comprises a semiconductor material and (b) is configured such that an interface resistance of the modulator is ≤ 4 Ohms. The interface resistance is a serial resistance between the interface layer and respective electrodes of the pluralities of segmented capacitive loading electrodes.

An optical modulator circuit includes first and second electrodes, first and second p-n junction segments (PNJSs), and first and second optical waveguides. The first PNJS includes a first modulating p-n junction (MPNJ) in series with a first non-modulating device (NMD) that are connected to the first and second electrodes, respectively, where the first NMD includes a first substantially larger capacitance than the first MPNJ. The second PNJS includes a second NMD in series with a second MPNJ that are connected to the first and second electrodes, respectively, where the second NMD includes a second substantially larger capacitance than the second MPNJ. The first and second optical waveguides superimpose the first and second MPNJs, respectively, where the first and second MPNJs are configured to modulate a refractive index of the first and second optical waveguides, respectively, based on the substantially larger capacitance of the first NMD and the second NMD.

An optical transmitter includes an optical modulator configured to modulate input light and output a light signal, a drive unit configured to output a modulation data signal to the optical modulator, and a bias controller configured to perform feedback control of bias voltage applied to the optical modulator. During a modulation OFF operation of the optical modulator, the bias controller switches a control target point from a first control target point to a second control target point and executes the feedback control.

An optical neural network is constructed based on photonic integrated circuits to perform neuromorphic computing. In the optical neural network, matrix multiplication is implemented using one or more optical interference units, which can apply an arbitrary weighting matrix multiplication to an array of input optical signals. Nonlinear activation is realized by an optical nonlinearity unit, which can be based on nonlinear optical effects, such as saturable absorption. These calculations are implemented optically, thereby resulting in high calculation speeds and low power consumption in the optical neural network.