Nec Corporation

Japan Aviation Electronics Industry, Limited

Mitsubishi Pencil Company, Limited

Yasuhiro Koike

Koike, Yasuhiro

Toshitaka Torikai

Hirohito Yamada

Tetsuro Okuda

Takayoshi Yamauchi

Shuichi Aihara

Masayuki Shiratori

Mitsuaki Kazou

Yuichi Koreeda

Naoki Katagiyama

Hitoshi Suzuki

Hiroshi Honmou

Masataka Itoh

Kikuo Makita

Satoshi Kai

Tomoji Terakado

Naohiko Moriya

Akihito Mitsui

Hiroyuki Muto

Jun-ichi Sasaki

Yoshimasa Sugimoto

Kenko Tagushi

A receptacle of an electrical-optical hybrid connector including a plug having an insertion fitting part and the receptacle having a housing space that receives the insertion fitting part includes an optical connection part disposed in a space in communication with the housing space, and an electrical connection part disposed in front of the optical connection part, a shutter that is opened when the receptacle and the plug are connected to each other is provided in front of the optical connection part of the receptacle, and the optical connection part of the receptacle moves forward in association with the shutter when the shutter is opened, and moves rearward in association with the shutter when the shutter is closed.

Electrical-optical hybrid connector and receptacle thereof

In order to fix an optical fiber to a desired position in a holding member easily and tightly, provided is an optical collimator () having a plastic optical fiber () and a cylindrical holder (). The holder () is configured to hold a collimator lens () at an end and has an insertion hole () at an opposite end for inserting the plastic optical fiber (). The plastic optical fiber () is sandwiched by an inner surface of a recess () which is formed at a part of the holder () in proper alignment with the collimator lens ().

Optical collimator and optical connector using same

In an optoelectrical connector that is composed of a plug including an insertion fitting part and a receptacle including a housing space into which the insertion fitting part of the plug is inserted, the plug is provided with an optical connection part on a front end of the insertion fitting part and an electric connection part more rearward than the optical connection part. The receptacle is provided with an optical connection part on the deep side of the housing space and an electric connection part more frontward than the optical connection part. A shutter is formed on the immediate front of the optical connection part of the receptacle and the shutter opens in the optical connection. Deterioration of optical coupling efficiency caused by attachment of metal abrasion powder, which is generated in a slide between the electrical connection parts in the electrical connection, to the optical connection parts, is prevented.

Optoelectrical connector

A light control apparatus includes a part for splitting an input light entering the light control apparatus through an optical fiber, a photoelectric conversion part for converting a monitor light into an electrical signal, and a third part for controlling the opening and closing of an optical transmission path for a signal light based on the electrical signal. The light power of an output light is controlled by the opening and closing amount of the optical transmission path which is controlled depending on the amount of the electrical signal output in accordance with the level of the monitor light. A semiconductor photovoltaic device capable of performing photoelectric conversion without using an external power source is used as the photoelectric conversion part. An optical shutter using a micromachine, or an optical device such as absorption-type modulator or refractive index-type modulator is used as the third part.

Light control apparatus having a device for controlling the input signal light of an optical transmission path

An optical module has an optical wave-guide structure formed on a silicon substrate and a laser diode array solder bonded to first pads patterned on the silicon substrate in a self-aligned manner by virtue of surface tension of solder during a reflow stage, and the first pads are shaped into a rectangular parallelopiped configuration so as to make a ratio of a solder bump height to a pad width large without decrease of the volume of the solder bump, thereby generating large surface tension.

Optical module having self-aligned optical element and optical

In a laser device in which a first cladding layer (11b) of InP of p-type, an active layer (12) of InGaAsP, and a second cladding layer (13) of InP of n-type are successively formed on a predetermined area of a base layer (10, 11a) of InP of p-type, a current confining structure includes, to confine a current in the active layer, a pair of first buried layers (14) of InP of p-type on a remaining area of the base layer, a pair of first current blocking layers (15) of InP of n-type on the pair of first buried layers, a pair of second current blocking layers (16) of a semi-insulating InP on the pair of first current blocking layers, and a second buried layer (17) of InP of n-type on the pair of second current blocking layers. The pair of first buried layers have a pair of projecting portions (14a) projecting over inner edge portions of the pair of first buried layers with the first cladding, the active, and the second cladding layers interposed between the pair of projecting portions and with the pair of projecting portions brought into contact with side surfaces of the active layer and with inner edge portions of the pair of second current blocking layers so that the pair of first current blocking layers are electrically isolated from the active layer. Instead of the pair of second current blocking layers, a pair of low carrier concentration layers (22) of InP of n-type (or p-type) and a pair of current blocking layers (23) of p-type may be successively formed on the pair of first current blocking layers.

Semiconductor laser device which makes it possible to realize high-speed

In a laser diode element including a front facet, a rear facet, a laser cavity formed between the front the rear facets and which has a predetermined length L, coating layers coated on the front facet to provide a reflectivity smaller than 5%, and an active layer and a uniform grating having regular corrugation formed in the direction of the laser cavity and which are coupled to each other at a predetermined coupling constant K, the laser diode element is specified by a product of the predetermined coupling constant and the predetermined length L and falling within a range between 0.4 and 1.0, both inclusive.

Laser diode element with excellent intermodulation distortion

In a laser diode element including a front facet, a rear facet, a laser cavity formed between the front rear facets and which has a predetermined length L, coating layers coated on the front facet to provide a reflectivity smaller than 5%, and an active layer and a uniform grating having regular corrugation formed in the direction of the layer cavity and which are coupled to each other at a predetermined coupling constant K, the laser diode element is specified by a product of the predetermined coupling constant and the predetermined length L and falling within a range between 0.4 and 1.0, both inclusive.

A distributed-feedback laser has a diffractive grating, an optical waveguide layer, and an active region. The optical waveguide layer has equivalent refractive indexes larger towards cavity end facets and smaller towards a device center portion along a cavity. The active region containing the optical waveguide layer has widths wider towards the cavity end facets and narrower towards the device center portion along the cavity. The optical waveguide layer has a uniform electric intensity distribution along the cavity to improve the linearity of current versus optical output characteristics. In another arrangement, the optical waveguide layer formed on the diffractive grating has in its compositions longer wavelengths towards the cavity end facets and shorter wavelengths towards the cavity center portion along the cavity, whereby the optical waveguide layer has a uniform optical intensity distribution along the cavity to improve the linearity of current versus optical output characteristics. The distributed-feedback laser provided is with improved analog modulation distortion characteristics.

Distributed-feedback laser with improved analog modulation distortion

In a planar type heterojunction avalanche photodiode comprising a light absorbing layer of a first conduction type provided on a substrate of the first conduction type, an avalanche multiplication layer of the first conduction type provided on a side of the light absorbing layer which is opposite to the substrate, and a conduction region of a second conduction type in contact with the avalanche multiplication layer, a high reflection film is provided on a side of the conduction region which is opposite to the avalanche multiplication layer. An anti-reflection film to which light is supplied is provided on a side of the substrate which is opposite to the light absorbing layer. The light is absorbed in the light absorbing layer substantially, and the remaining light which is not absorbed in the light absorbing layer is reflected by the high reflection layer. The reflected light is absorbed in the light absorbing layer. Consequently, both a wide bandwidth and a high sensitivity are obtained.

Planar type heterojunction avalanche photodiode

A planar heterojunction avalanche photodiode (APD) having a first semiconductor layer of a first conductivity type for generating carriers by absorbing light, a second semiconductor layer of the same first conductivity type having an impurity concentration which decreases with the distance from the first semiconductor layer and a bandgap greater than that of the first semiconductor layer for avalanche-multiplying the carriers injected from the first semiconductor layer. A first semiconductor region of a second conductivity type is diffused in the second semiconductor layer at a prescribed depth from the upper surface of the second semiconductor layer thus forming a stepwise p-n junction. A guard-ring of the second conductivity type is formed in the second semiconductor layer to overlap the circumferential part of the first semiconductor region and forming a linearly graded p-n junction with the second semiconductor layer in a position closer to the first semiconductor layer than the stepwise p-n junction.

Planar heterojunction avalanche photodiode

A planar type heterostructure avalanche photodiode comprises first and second semiconductor layers having first and second forbidden energy gaps. The second forbidden energy gap is larger than the first forbidden energy gap. In the second semiconductor layer, the second forbidden energy gap is increased as a distance is increased from a hetero-interface between the first and second semiconductor layers, and a pn junction is provided. A cross sectional shape of the outer periphery of the pn junction is defined by a curvature dependent on the increase of the second forbidden energy gap.

Planar type heterostructure avalanche photodiode

An avalanche photodiode having a semiconducting light absorbing layer and an overlying avalanche gain layer of wide band-gap. The usual heavily doped region is formed in the avalanche gain region to form an abrupt p-n junction. Two semiconducting guard rings are formed around the heavily doped region. The doping of both rings provide graded p-n junctions with the avalanche gain layer. The inner guard ring extends more deeply into the avalanche gain layer than either the outer ring or the heavily doped region.

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Tokyo, Japan

Toshitaka Torikai