Sharp Kabushiki Kaisha Corporation

501 Sharp Kabushiki Kaisha

Saburo Yamamoto

Hiroshi Hayashi

Takahiro Suyama

Toshiro Hayakawa

Taiji Morimoto

Osamu Yamamoto

Kohsei Takahashi

Seiki Yano

Masafumi Kondo

Kazuaki Sasaki

Nobuyuki Miyauchi

Shigeki Maei

Masaki Kondo

Sadayoshi Matsui

Mitsuhiro Matsumoto

Mototaka Taneya

Toshihiko Yoshida

Shinji Kaneiwa

Masanori Watanabe

Hidenori Kawanishi

Hiroshi Nakatsu

Takehiro Shiomoto

Masahiro Hosoda

Haruhisa Takiguchi

Hiroyuki Hosoba

Kosei Takahashi

Toshimasa Hamada

Tadashi Takeoka

Masumi Nakamichi

Shohichi Kato

Nobuybuki Miyauchi

Hiroshi Kayashi

Noboyuki Miyauchi

Taiji Morimato

A hyper-resolution optical device which can focus a beam of light to a diameter less than the diffraction limit. The optical device has an optical system disposed on a transmissive substrate. One component in the optical system is a hyper-resolution optical component which passes or reflects light and which has a central portion which does not pass or reflect light, respectively. The hyper-resolution optical component can be integrated with the transmissive substrate. Such optical devices are particularly suitable for optical pick-up devices, laser printers, sensors.

Hyperresolution optical system

A semiconductor light emitting device which allows part of an active layer to generate light by supplying current to the part of the active layer is disclosed. The semiconductor light emitting device includes: a semiconductor substrate having upper and lower surfaces, the upper surface having a stepped portion, the stepped portion dividing the upper surface into at least a first area and a second area; a current confining layer, formed on the upper surface of the substrate, the current confining layer being discontinuous at the stepped portion, the current flowing through an area between the first area and the second area of the substrate; a multilayer structure formed on the current confining layer, the multilayer structure including the active layer; a first electrode which covers only part of an upper surface of the multilayer structure; and a second electrode formed over the lower surface of the substrate. In the semiconductor light emitting device, the light generated from part of the active layer is extracted to the outside through a portion of the upper surface of the multilayer structure which is not covered with the first electrode.

Semiconductor light emitting device with current confining layer

A semiconductor laser device is disclosed which emits laser light from a facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an AlGaAs active layer for laser oscillation, and a protective film formed on the facet, wherein a film containing sulfur is provided between the facet and the protective film.

Method for the production of a semiconductor laser

A semiconductor laser device is provided which is constituted by semiconductor materials so as to emit laser light from a cavity end facet, the laser light being excited in a waveguide within an active layer sandwiched between a pair of cladding layers, wherein a window layer made of a semiconductor material having a band gap greater than that of the active layer is formed on the cavity end facet from which the laser light is emitted, so as to have a thickness sufficient to prevent local generation of crystal defects by lattice mismatching between the semiconductor material of the window layer and the semiconductor materials at the cavity end facet. There is also provided a method for producing such a semiconductor laser device with high efficiency.

Semiconductor laser device and a method for producing the same

Semiconductor laser device with a sulfur-containing film provided

An optical information processing apparatus which includes a substrate of a transparent material, first and second optical waveguides formed on opposite faces of said transparent substrate, a light introducing device for introducing reflected light from an information writing medium into the first and second optical waveguides, and a detecting device for detecting a reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into the first and second optical waveguides.

Optical information processing apparatus

A window semiconductor laser device comprising a stripe-channeled substrate, an active layer for laser oscillation and a cladding layer disposed under the active layer, wherein the surface of the active layer is flat and the thickness of the portion of the active layer corresponding to the striped channel of said substrate in each of the window regions in the vicinity of the facets is thinner than that of the portion of the active corresponding to the striped channel of said substrate in the stimulated region positioned between the window regions.

Epitaxial growth process for the production of a window semiconductor

A semiconductor laser device and a method for the production of the semiconductor laser device are provided, which semiconductor laser device includes a striped channel formed in a semiconductor substrate through a current blocking layer on the substrate and at least two dummy grooves formed in the current blocking layer on each side of the striped channel. Also provided are a semiconductor wafer prepared for the purpose of producing optical devices with an optical waveguide, and a method for the production of the semiconductor wafer. The semiconductor wafer includes a semiconductor substrate, the surface of which has an orientation inclined from the [100] direction to one of the [011] and [011] directions of an angle .theta. satisfying the relationship 0.1.degree.&lt;.vertline..theta..vertline.&lt;4.degree.; a plurality of striped channels formed in a substrate through a current blocking layer in the direction of the other of the [011] and [011] directions; and at least one dummy side groove formed between the striped channels, having a combined cross-sectional area on the plane perpendicular to the other direction greater than that of each of the striped channels.

Semiconductor laser device, a semiconductor wafer

A semiconductor laser device is disclosed which comprises a semiconductor substrate, a striped mesa disposed on the substrate and having an active layer for laser oscillation, a current injection layer disposed on the striped mesa and having a width smaller than that of the striped mesa, and a burying layer disposed on both sides of the current injection layer so as to come into contact with the side walls of the current injection layer, the burying layer being capable of absorbing laser light produce in the active layer and of preventing current from flowing through the outside of the striped mesa.

Semiconductor laser device

There is disclosed a semiconductor laser device with a strip-channeled substrate and a double-heterostructure multi-layered crystal disposed over the substrate, the multi-layered crystal containing an active layer for laser oscillation. This semiconductor laser device comprises an optical waveguide that a semiconductor laser device with a stripe-channeled substrate and a double-heterostructure multi-layered crystal disposed over the substrate, the multi-layered crystal containing an active layer for laser oscillation, which semiconductor laser device comprises: an optical waveguide that is formed within the active layer just above the striped channel of the substrate based on a decrease in the effective refractive index due to the striped channel, the outside of which absorbs a laser beam produced in the active layer; a striped mesa that is formed by the removal of the portions of the multi-layered crystal corresponding to the outside of the optical waveguide; and a plurality of burying layers that are grown into the removed portions to prevent the diffusion of carrier in the transverse direction within the active layer.

A semiconductor laser device with a protective film on the facets, wherein said protective film is made of a multi-layered dielectric film composed of alternate layers consisting of at least two kinds of dielectric film, one of which is a first dielectric film of low refractive index and the other of which is a dielectric film of high refractive index, said multi-layered dielectric film which covers at least one of the facets therewith being a light-permeable film with a reflectivity of 30% or less.

Semiconductor laser device with a protective film on the facets

An optical information processing apparatus including a substrate of a transparent material, first and second optical waveguides formed on opposite faces of said transparent substrate, a light introducing device for introducing reflected light from an information writing medium into the first and second optical waveguides, and a detecting device for detecting reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into the first and second optical waveguides.

A semiconductor apparatus comprises a step-shaped substrate and a multiple-layered crystal structure formed on the substrate, said multiple-layered crystal structure is of a superlatticed layer which is composed of alternate layers consisting of plural thin layers grown by molecular beam epitaxy.

Semiconductor apparatus

A semiconductor laser device comprising an active layer sandwiched between a first semiconductor layer and a second semiconductor layer, the forbidden bandgap of each of said first and second layers being larger than that of said active layer, wherein at least one of said first and second layers has a striped projection provided with two inclined surfaces; said layer is sandwiched between said active layer and a light absorption layer; and the thickness of said layer that corresponds to the inside of the center area of each of the two inclined surfaces is thick enough so that laser light cannot permeate into said absorption layer and the thickness of said layer that corresponds to the outside of the center area of each of the two inclined surfaces is sufficiently thin so that laser light can permeate into said absorption layer, whereby the thickness of a semiconductor layer that constitutes a double-heterostructure is not required to be precisely regulated so that the laser device is not restricted by production conditions and mass-production.

A semiconductor laser device, includes (1) a first semiconductor layer having a mesa-shaped stripe, (2) a current blocking layer applied on the first semiconductor layer except the top of the mesa-shaped stripe of the first semiconductor layer, the current blocking layer allowing the electric current to flow only through the mountain-shaped region, (3) a first cladding layer applied on the current blocking layer and on the top of the mountain-shaped stripe of the first semiconductor layer, and having charge carriers of the same type with that of the first semiconductor layer, (4) an active layer applied on the first cladding layer, and (5) a second cladding layer applied on the active layer, and having charge carriers of the type opposite to that of the first cladding layer, wherein the first cladding layer, the active layer and the second cladding layer compose a multilayer structure of the double heterojunction type for the laser excitation. The first cladding layer is thin so that the laser light excited in the active layer reaches the current blocking region that is outside the mesa-shaped region while it hardly reaches the first semiconductor layer through the mesa-shaped region.

Growing community of inventors

Nara, Japan

Saburo Yamamoto