Nec Corporation

Yoshiharu Tashiro

Kenichi Kasahara

Ichiro Ogura

Shigeru Kawai

Mitsunori Sugimoto

Keiichi Kubota

Takahiro Numai

A driving method for a pnpn semiconductor device includes the steps of applying a voltage higher than a holding voltage of the pnpn semiconductor device to an anode electrode thereof, supplying a control signal light to the pnpn semiconductor device to set the pnpn semiconductor device into an ON state, and supplying an information signal light to the pnpn semiconductor device to emit an output light. The control signal light and the information signal light are time-sequentially supplied to the pnpn semiconductor device under the voltage applied thereto. An apparatus for carrying out the driving method includes a light information transmission input line that is branched into a plurality of lines, where a light detection circuit is coupled to at least one of the lines. A synchronous driving circuit applies voltage to the pnpn semiconductor device which is coupled to one of the other lines of the information transmission input line. The pnpn semiconductor device is driven by receiving light from the input line when the light detection circuit detects an address of the pnpn semiconductor device included in a light supplied from the light information transmission input line.

Driving method and apparatus for a pnpn semiconductor device

A matrix of optical functional devices are divided into plural device units. Each of the device units includes at least two optical functional devices having light transmitting coatings. The coatings have transmission factors which are different from each other. Light signals emitted through the coatings from the at least two optical functional devices in each unit are received by a corresponding light receiving device among light receiving devices arranged in a one-dimensional pattern. In each device unit optical functional devices to be driven are selected, so that a coupling degree between each device unit and the corresponding light receiving device is changed.

Optical interconnection apparatus

A semiconductor optical memory includes a gate layer composed of a p- first semiconductor layer, a p- or n- second semiconductor layer, and an n- third semiconductor layer provided between a cathode layer and an anode layer. Where the second layer is of n- type, an impurity concentration of the n- second semiconductor layer is lower than an impurity concentration of the n- third semiconductor layer, and a bandgap eneray of the n- third semiconductor layer is lower than bandgap energies of the cathode and anode layers. Where the second layer is of p- type, an impurity concentration of the p- second semiconductor layer is lower than an impurity concentration of the p- first semiconductor layer, and a bandgap energy of the p- first semiconductor layer is lower than bandgap energies of the cathode and anode layers. As a result, a response speed becomes as fast as several 100 Mb/s.

Semiconductor optical memory having a low switching voltage

At least one electric pulse having a predetermined voltage which is higher than a switching voltage for a pnpn semiconductor device and a predetermined width is applied across the pnpn semiconductor device. The electric pulse width is set not to turn the pnpn semiconductor device on. Consequently, a predetermined amount of carriers are accumulated in the pnpn semiconductor device. In this circumstance, a trigger light is supplied to the pnpn semiconductor device to be turned on. As a result, an energy of the trigger light is largely decreased as compared to a conventional method.

Method for driving a pnpn semiconductor device

A laser diode and an optical switching device are connected in parallel relative to a power supply. The optical switching device is turned on by receiving an input light, and stores the ON state, so that the laser device is turned off. As a result, an electric power consumption is decreased, the structure is simplified, and the adjustment becomes easy.

Optical logic device with PNPN detection and laser diode output

A space modulation matrix is composed of semiconductor transmittivity modulation elements arranged in a matrix pattern. A transmittivity of the transmittivity modulation elements is changed by supplying a light or applying a voltage greater than a switching voltage of the transmittivity modulation elements to a selected number of the transmittivity modulation elements, so that a space modulation is provided on the space modulation matrix, and is renewed by any number of times.

Semiconductor device for a space modulation matrix and method for

A method for driving an optoelectronic switching device such as a pnpn semiconductor device comprises applying a predetermined biased voltage to the optoelectronic semiconductor device, and supplying plural light inputs to the optoelectronic semiconductor device to which the predetermined biased voltage is applied. The plural light inputs are supplied to the optoelectronic semiconductor device intermittently with a predetermined period before carriers excited by a first input pulse of the plural light inputs become extinct. As a result, the number of light sources is decreased.

Method for driving an optoelectronic switching device

An optical semiconductor device comprises cathode and anode regions, and a gate region having a forbidden band gap narrower than those of the cathode and anode regions. The gate region is sandwiched by the cathode and anode regions. The optical semiconductor device further comprises a plurality of windows for receiving and radiating lights so that the alignment of light axes can be easily performed for a plurality of input and output lights.

Optical semiconductor device

A process for controlling an optical pnpn thyristor to be driven comprises a step of applying a train of pulses to maintain a low impedance state of an optical pnpn thyristor which is shifted beforehand to be in the low impedance state by a positive set pulse. Each of the train of pulses is less than in its level than the positive set pulse. When light emission is required for the reading of an information, a positive set pulse is applied to the optical pnpn thyristor. As a result, electric power consumption is reduced during a time storing the information.

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Tokyo, Japan

Yoshiharu Tashiro