Mitsubishi Denki Kabushiki Kaisha

Keisuke Kojima

Kazuo Kyuma

Susumu Noda

Yasunori Tokuda

Kunihiko Hara

Shuichi Tai

Jun Ohta

Masanobu Takahashi

Yoshinori Nomura

Kenzo Fujiwara

Teruhito Matsui

Noriaki Tsukada

Toshio Shinnishi

Masaaki Kameya

Koichi Hammanaka

A learning method for a neural network, in which at least a portion of the interconnection strength between neurons takes discrete values, includes the steps of updating an imaginary interconnection strength taking continuous values by using the quantity of update of the interconnection strength which has been calculated by using the discrete interconnection strength, and discretizing the imaginary interconnection strength so as to provide a novel interconnection strength.

Learning method for neural network having discrete interconnection

An optical logic element includes an optical bistable npnp element for switching from a high resistance state to a low resistance state in response to electrical bias and incident light energy in which the switching time becomes shorter as the incident light energy becomes larger. The elements emit light in the low resistance on state. The optical logic element is designed for analog threshold processing of light energy. A plurality of optical bistable elements connected in parallel differentially threshold process incident light energy. An opto-electronic conversion apparatus includes linear arrays of light emitting elements, a two-dimensional array of optical memories, i.e., optical bistable elements, and linear light receiving element arrays arranged transverse to the light emitting element arrays, all integrated with each other. Corresponding light emitting elements, optical memories, and light receiving elements permit arbitrary transfers of signals. Periodic refresh light pulses maintain each optical memory in an established state.

Optical logic element with short switching time

In a light-responsive semiconductor device in which the laser oscillation state is controlled by incident light, a layer of material having a conductivity modulatable by light is integrated in a semiconductor laser structure and is responsive to the incident light for the control of the laser oscillation state of the device. In one embodiment constituting a light logic element, a plurality of semiconductor lasers are integrated on a substrate with each respective semiconductor laser having a grating along the entirety or a portion thereof and provided with a light waveguide connecting with a waveguide of an adjacent semiconductor laser. In a bistable semiconductor laser there are provided two different conductivity type light confinement layers, an active layer comprising a multiple quantum well structure which is between the two light confinement layers, a grating provided close to the quantum well active layer. The oscillation wavelength established by the grating is shorter than the peak gain wavelength produced by the quantum well active layer.

Semiconductor laser device

A surface-emitting semiconductor laser device comprises a first electrode, a first-conductivity-type clad layer provided on the first electrode, an active layer provided on the first-conductivity-type clad layer, a guide layer provided on the active layer and having an even-numbered-order diffraction grating opposite to the active layer, a second-conductivity-type clad layer provided on the guide layer, contact layers provided on portions of the second-conductivity-type clad layer, and second electrodes provided on the contact layers.

Surface-emitting semiconductor laser device

A semiconductor laser having an active layer of quantum well structure, where the resonator loss is enhanced thereby to conduct an oscillation at a high quantum level.

Growing community of inventors

Amagasaki, Japan

Keisuke Kojima