An electrode structure includes: a metal film with an opening formed in a part of the metal film; and a transparent conductive film disposed in the opening, wherein the transparent conductive film is electronically connected to an element and overlaps with the element as viewed in a plan view in a thickness direction of the transparent conductive film.

The present invention relates to a communication system for receiving electromagnetic radiation (EMR) signals from a plurality of sources or directions. A communication system comprises a transmission section surrounding an antenna section. The transmission section can be made of concentric layers of lens elements, mirror elements, or refraction medium. The layers allow incoming EMR to be directed to the antenna section through reflection or refraction. The antenna section can be made of a plurality of antenna elements such that each antenna element detects incoming EMR signals from different angles of origin even when the signals are received simultaneously.

An optical device includes a slot waveguide, and an electrode that has a coplanar structure including a signal electrode and a ground electrode disposed parallel to the slot waveguide. Furthermore, the optical device includes a plurality of electro-optical polymers each of which is inserted into a slot provided in the slot waveguide in a split state, and a bridge that is disposed in a boundary region located between the split electro-optical polymers and that electrically connects the ground electrode and another ground electrode.

A pixel circuit having a function of compensating for characteristic variation of an electro-optical element and threshold voltage variation of a transistor is formed from a reduced number of component elements. An input signal is sampled from a signal line so as to be held in a holding capacitor. The threshold voltage of the drive transistor is imparted to the holding capacitor in order to cancel an influence of the threshold voltage.

A wireless transmitter/receiver generates a first signal which notifies timing of a time slot allocated to each wireless station device, a conversion unit converts the first signal into an optical signal, and each of a plurality of antenna units converts the first signal from the optical signal into an electrical signal and transmits the electrical signal wirelessly. The wireless station device transmits a second signal at the timing reported by the first signal. Each of the plurality of antenna units converts the second signal wirelessly received from each wireless station device into an optical signal, and the conversion unit converts the second signal from the optical signal into an electrical signal. The wireless transmitter/receiver calculates, for each wireless station device, a transmission delay by using a difference between a reception time of the second signal and a reception time of a signal transmitted at the allocated timing by the wireless station device when it is assumed that there is no transmission delay. The wireless transmitter/receiver determines guard time between the time slots allocated to the wireless station devices based on the transmission delays of the wireless station devices.

Methods and systems for a low-voltage integrated silicon high-speed modulator may include an optical modulator comprising first and second optical waveguides and two optical phase shifters, where each of the two optical phase shifters may comprise a p-n junction with a horizontal section and a vertical section and an optical signal is communicated to the first optical waveguide. A portion of the optical signal may then be coupled to the second optical waveguide. A phase of at least one optical signal in the waveguides may be modulated utilizing the optical phase shifters. A portion of the phase modulated optical signals may be coupled between the two waveguides, thereby generating two output signals from the modulator. A modulating signal may be applied to the phase shifters which may include a reverse bias.

Provided is a multi-channel, bi-directional optical communication module. The multi-channel, bi-directional optical communication module includes a transmission unit transmitting an optical transmission signal for each of a plurality of channels, a multiplexer multiplexing the transmitted optical transmission signal for each of the plurality of channels to output a multi-channel optical transmission signal, a circulator passing the multi-channel optical transmission signal output from the multiplexer therethrough to transmit the multi-channel optical transmission signal to an optical fiber and reflecting a multi-channel optical reception signal received from the optical fiber, a demultiplexer demultiplexing the multi-channel optical reception signal reflected from the circulator to output an optical reception signal for each of the plurality of channels, a reception unit receiving the output optical reception signal for each of the plurality of channels and converting the received optical reception signal into an electrical signal for each of the plurality of channels, and a body unit in which the transmission unit, the multiplexer, the circulator, the demultiplexer, and the reception unit are disposed, in which a wavelength of the optical transmission signal for each of the plurality of channels is the same as a wavelength of the optical reception signal for each of the plurality of channels, and the circulator includes a first optical filter which passes a multi-channel optical transmission signal incident to a surface thereof therethrough and reflects a multi-channel optical reception signal incident to the other surface thereof, and a second optical filter which is disposed in parallel with the first optical filter and reflects the multi-channel optical reception signal reflected from the first optical filter to the demultiplexer.

Provided is an optical transmitter having improved frequency characteristics by controlling the band by using components constituting the optical transmitter. An optical transmitter including an optical modulator that includes a traveling-wave electrode and a terminating resistor, and an optical modulator driver configured to drive the optical modulator, in which a characteristic impedance of a transmission line connecting the optical modulator driver and the optical modulator is 20% or more higher than a characteristic impedance of the optical modulator, and an electrical length of the transmission line is 1/20 or more and ½ or less of a wavelength corresponding to a 3 dB band frequency of an electrical signal driving the optical modulator.

Disclosed herein are methods, devices, and system for beam forming and beam steering within ultra-wideband, wireless optical communication devices and systems. According to one embodiment, a free space optical (FSO) communication apparatus is disclosed. The FSO communication apparatus includes a semiconductor optical device configured to have a transient response time of less than 500 picoseconds (ps), a lens, and a first band select filter.

Provided is a print circuit board including: a ground conductor layer; a pair of strip conductors extending along a first orientation; a first resonator conductor three-dimensionally intersecting with the pair of strip conductors along a second orientation; a pair of first via holes connecting the first resonator conductor and the ground conductor layer; and a dielectric layer including the first resonator conductor therein, and being disposed between the ground conductor layer and the pair of the strip conductors. A distance H.sub.1 between the pair of strip conductors and the ground conductor layer is twice or more a distance H.sub.2 between the pair of strip conductors and the first resonator conductor, and a line length L of the first resonator conductor is 0.4 wavelength or more and 0.6 wavelength or less at a frequency corresponding to the bit rate.