Ricoh Company, Ltd.

Ricoh Research Institute of General Electronics Co., Ltd.

Shiro Satoh

Hiroshi Kondoh

Yasuhiro Osawa

Noriaki Onodera

A semiconductor light emitting element has a semiconductor laminating structure formed on a semiconductor substrate and having a junction portion formed in parallel with a semiconductor substrate face; a light generating portion formed in the vicinity of the junction portion such that an electric current can be injected into the light generating portion; a light emitting end face approximately perpendicular to the junction portion and approximately having an arc or hyperbolic shape in a direction parallel to the semiconductor substrate face; and an electrode for electric current injection formed in an upper portion of the semiconductor laminating structure and arranged in a position separated from at least a center of curvature of the arc light emitting end face. The semiconductor light emitting element has a shape of the light emitting portion and a layer structure capable of controlling a radiant angle of light. Since the light emitting end face is formed in an arc shape, a full angle at half maximum of emitted light in a horizontal direction with respect to the substrate face can be reduced in comparison with a case in which the light emitting end face has a linear shape. Optical coupling efficiency with respect to an optical fiber and a lens system can be improved.

Semiconductor light emitting element

An analog signal having a value A is converted into an n-bit digital signal. An optical calculation part performs a part of a calculation shown below for an A/D conversion as below.

Optical A/D conversion using asymmetrical-neural-networks

An optically functional device has a semiconductor substrate, a light receiving portion disposed on the semiconductor substrate for receiving input light, a light emitting portion disposed on the light receiving portion for emitting output light, a window disposed above the light emitting portion, through which input light and output light pass and a resistance layer made of a semiconductor for functioning as load resistance. The resistance layer is disposed at least in either place between the semiconductor substrate and the light receiving portion, or between the light receiving portion and the light emitting portion, or on the light emitting portion. The light emitting portion has a light emitting layer made of semiconductor material having an energy of forbidden band width of more than the energy of a main peak of input light. The light receiving portion has a base and a collector each of which is made of a semiconductor material having an energy of forbidden band width equal to or less than the energy of a main peak of input light. The light emitting portion is adapted to feed back a part of the output light to the light receiving portion. Thereby a nonlinear output response to input light is performed based on the feedback effect of the output light absorbed by the light receiving portion.

Optically functional device with integral resistance layer

An optical functioning element comprising: an optical functional element having a layer-stacked structure including a crystalline substance layer; a substrate for mounting the optical functional element; and an epitaxial growth layer of the crystalline substance formed between the optical functional element and the substrate. The substrate becomes transparent with respect to the light accessible to the optical functional element so that it becomes possible to optically access the functional element from both sides of the substrate without partly removing the substrate for passing through the light.

Optical functioning element using a transparent substrate with matching

A semiconductor light emitting element that includes a substrate having an upper surface, a multi-layered semiconductor stacked structure formed on the upper surface of the substrate. The multi-layered stacked structure emits light when a current is applied and passes through the structure. The element further includes a first electrode disposed on the multi-layered stacked structure and a second electrode disposed aside the multi-layered stacked structure on the upper surface of the substrate. The second electrode constitutes a counter electrode for the first electrode.

A semiconductor light emitting device comprises a semiconductor substrate of a first conductivity type; an electric current blocking layer formed on one main face of the substrate and including a semiconductor of a second conductivity type opposite to the first conductivity type and having an opening reaching the main face; a first semiconductor layer of the first conductivity type formed on the electric current blocking layer and a portion of the main face on which the opening is disposed; a second semiconductor layer stacked on the first semiconductor layer and forming a hetero-junction together with the first semiconductor layer; a semiconductor layer for electrode of the second conductivity type formed on the second semiconductor layer and having a window reaching the second conductor layer in a position corresponding to the opening; a first electrode metallic layer formed on the electrode semiconductor layer except for the window; and a second electrode metallic layer formed on the other main face of the substrate. The window has a flat shape composed of a substantially circular or rectangular shape and has a size substantially less than the size of the opening. Portions of the first and second semiconductor layers corresponding to the opening function as a light emitting region by flowing an electric current between the first and second electrode metallic layers, and a light generated from the light emitting region is outputted through the window in a direction substantially perpendicular to the substrate.

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Ogawara, Japan

Shiro Satoh