Sanyo Electric Co., Ltd.

Sanyo Electric Oc., Ltd.

Kazushi Mori

Atsushi Tajiri

Minoru Sawada

Yasuaki Inoue

Takenori Goto

Akira Ibaraki

Koji Tominaga

Mitsuaki Matsumoto

Koutarou Furusawa

Takao Yamaguchi

Masayuki Shono

Daisuke Ide

Naoyuki Takagi

Katsutoshi Hibino

Keiichi Yodoshi

Yasunori Inoue

Yasuhiko Nomura

Yoshio Okayama

Hitoshi Hirano

Kenji Nagatomi

Ryoji Hiroyama

Naoteru Matsubara

Kenji Asano

Shingo Kameyama

Tadao Toda

Toyozo Nishida

Yasuhiro Ueda

Tatsuhiko Niina

Yuuki Ota

Shogo Suzuki

Hideyuki Nonaka

A semiconductor laser device includes a Si(100) substrate in which a recess having an opening and a bottom face surrounded by inner wall surfaces is formed, a semiconductor laser element placed on the bottom face, and a translucent sealing glass, mounted on top of the Si(100) substrate, which seals the opening. The laser light emitted from the semiconductor laser element is reflected by a metallic reflective film formed on the inner wall surface and then transmits through the sealing glass so as to be emitted externally.

Semiconductor laser device, optical pickup device and semiconductor device

An optical element is disposed on an optical path between a beam branching element and a photodetector. The optical element is disposed at a focal position of a stray light beam reflected by a recording layer except a target recording layer, and shields or attenuates the light beam in a region where the stray light beam converges.

Optical pick-up capable of eliminating stray beams

A diffraction element is disposed between a beam branching element (such as a beam splitter) and a photodetector. The diffraction element further segment an interference fringe introduced into stray light by a diffraction grating which divides a laser beam emitted from a laser beam source into a main beam and two sub-beams.

Optical pickup device

A method of manufacturing an element having a microstructure of an excellent grating groove pattern or the like is obtained. This method of manufacturing an element having a microstructure comprises steps of forming a metal layer on a substrate, forming a dot column of concave portions on the surface of the metal layer and anodically oxidizing the surface of the metal layer formed with the dot column of concave portions while opposing this surface to a cathode surface thereby forming a metal oxide film having a grating groove pattern. When the interval between the concave portions of the dot column is reduced, therefore, a linear grating groove pattern having a large depth with a uniform groove width along the depth direction is easily formed in a self-organized manner.

Element having microstructure and manufacturing method thereof

Method of forming grating microstrutures by anodic oxidation

In a holographic pattern provided in a holographic optical element, a patterntwists a diffracted light beam in a clockwise direction, to form a semi-circular light spot Sa on photodetection parts A and B so as to extend over a dividing line LX in a four-segment photodetection part. A patternsimilarly twists the diffracted light beam in a clockwise direction, to form a semi-circular light spot Sb on photodetection parts C and D so as to extend over a dividing line LX in the four-segment photodetection part.

Holographic optical element, position shift detecting apparatus, optical pickup apparatus, optical recording medium drive and method of fabricating holographic optical element

The present invention provides a wave plate capable of obtaining preferable phase conversion characteristic over a wide wavelength range. The wave plate includes an aluminum oxide film having linear grating groove patterns. The period L (&#x3bc;m) and the duty ratio De of the grating groove patterns are set at values within the first range specified by the following four formulas:L&#x2266;0.65&#x2267;2&#xd7;10&#x2266;6.0317&#x2212;10.3525.0516(&#x2212;0.85)/0.44+(&#x2212;0.41)/0.39&#x2266;1

Wave plate and optical device using the same

A surface emission semiconductor laser device capable of substantially completely controlling the plane of polarization is obtained. This surface emission semiconductor laser device comprises a first multi-layer reflector, an emission layer formed on the first multi-layer reflector and a second multi-layer reflector formed on the emission layer, and at least either the first multi-layer reflector or the second multi-layer reflector includes a striped part worked in a striped manner in a prescribed period.

Surface emission semiconductor laser device

Method of forming grating microstructures by anodic oxidation

A six-segment holographic surface is divided into regions by dividing lines. A four-segment photodetection part is divided into four photodetection parts equal in area by a section line substantially parallel to the radial direction of an optical disk and a section line orthogonal thereto. A main light beam diffracted in the regions of the six-segment holographic surface are condensed as spots at positions apart from each other on opposite sides on a section line of the four photodetection parts, and the main beam diffracted in the regions is condensed as spots in the center of the photodetection parts of the four-segment photodetection part.

Optical pickup with a diffraction element consist of six regions providing spatial variation corresponding to a focas state

A grating surface of a diffraction grating diffracts a laser beam emitted from a semiconductor laser device in &plusmn;1st order directions. The grating surface is formed in a rectangular or elliptic shape in such dimensions that a light spot formed on an objective lens by &plusmn;1st order diffracted beams is located in an aperture of the objective lens and not displaced from the aperture even if the objective lens is horizontally moved in a tracking operation. A grating surface of another diffraction grating has a width smaller than the width of an overlap region of a light spot on the diffraction grating corresponding to a part of a beam, diffracted in the &plusmn;1st direction, entering an objective lens and a light spot on the diffraction grating corresponding to a part of a beam, diffracted in the &minus;1st direction, entering the objective lens.

Optical pickup apparatus employing an adjusting circuit

A grating surface of a diffraction grating diffracts a laser beam emitted from a semiconductor laser device in &plusmn;1st order directions. The grating surface is formed in a rectangular or elliptic shape in such dimensions that a light spot formed on an objective lens by &plusmn;1st order diffracted beams is located in an aperture of the objective lens and not displaced from the aperture even if the objective lens is horizontally moved in a tracking operation. A grating surface of another diffraction grating has a width smaller than the width of an overlap region of a light spot on the diffraction grating corresponding to a part of a beam, diffracted in the &plus;1st direction, entering an objective lens and a light spot on the diffraction grating corresponding to a part of a beam, diffracted in the &minus;1st direction, entering the objective lens.

Optical pickup apparatus capable of suppressing offset of a tracking error signal

First and second photodiodes are arranged on the upper surface of a stem, returned light beams diffracted in the &plus; 1st order by a transmission type holographic optical element are received by the first photodiode, while returned light beams diffracted in the &minus; 1st order are received by the second photodiode. The first photodiode has a plurality of light receiving regions, and respectively outputs a reproducing signal, a focus error signal and a tracking error signal on the basis of the returned light beams. On the other hand, the second photodiode has a single light receiving region, and outputs a reproducing signal on the basis of the returned light beams.

Optical pickup apparatus and optical recording medium drive employing the same including a first photo receiving element for detecting the state of light beam and a second photo receiving element for reproducing information

Growing community of inventors

Hirakata, Japan

Kazushi Mori