Sony Corporation

Kohoku Kogyo Co., Ltd.

Kenji Sahara

Masato Doi

Hironobu Narui

Osamu Matsuda

Kanji Takeuchi

Hiroaki Ono

Takashi Kato

Kazuma Aiki

Yuko Ota

Yoshinobu Higuchi

A variable optical attenuator in which a polarization beam splitter splits a beam incoming from the front into two linearly-polarized beams perpendicular to each other and separately outputs them to the back along first and second light paths. A Faraday rotator rotates a polarization plane of the two incoming linearly-polarized beams to an arbitrary angle by controlling a magnetic field to be applied to a Faraday element by a magnetism applying means and outputs them to the back. First and second analyzers arranged in the first and the second light paths and parallelly arranged perpendicular to these light paths are arranged in that order. The two analyzers have optical axes perpendicular to each other so that the optical axes are in the same direction as that of the polarization plane of the two linearly-polarized beams output from the polarization beam splitter.

Variable optical attenuator

A laser diode capable of reducing a radiating angle &#x3b8;&#x22a5; in the vertical direction, an optical pickup device, an optical disk apparatus, and optical communications equipment, all equipped with the laser diode which increases optical coupling efficiency. It has a first cladding layer of the first conductive type formed on a substrate, with an active layer on top of the first cladding layer and a second cladding layer of the second conductive type on top of the active layer. In at least the first or second cladding layer, it is formed of at least one optical guide layer having a higher refractive index than the first or second cladding layer and operating to expand a beam waist in the waveguide. This operation contributes to widening a region in which to shut up light, enabling a radiating angle &#x3b8;&#x22a5; in the vertical direction to be reduced.

Laser diode, optical pickup device, optical disk apparatus, and optical communications equipment

In an optical head device, a light emission source for emitting a plurality of laser beams with different wavelengths and an optical system including an objective lens and a collimator are provided. With respect to the optical system to be used in common for a plurality of optical recording media of different kinds, the RIM intensity is set to be not less than 0.1 and the magnification is set in the range of 4 to 6. With these conditions applied to the RIM intensity and the magnification of the optical system, light utilization efficiency at the time of CD recording is ensured, while preventing this from adversely affecting DVD reproduction or recording and while ensuring a beam spot quality.

Optical head device and information processing apparatus

A semiconductor laser comprises: a substrate, a first cladding layer on the substrate, an active layer on the first cladding layer, a second cladding layer on the active layer; and the second cladding layer has a plurality of steps of equivalent complex index of refraction disposed to be parallel to p-n junction direction and to be perpendicular to a cavity direction. In an optical pickup device using a semiconductor laser as a light source thereof, the semiconductor laser comprises: a substrate, a first cladding layer on the substrate, an active layer on the first cladding layer, a second cladding layer on the active layer; and the second cladding layer has a plurality of equivalent complex index of refraction disposed to be parallel to p-n junction direction and to be perpendicular to a cavity direction. In an optical record and/or reproducing apparatus using semiconductor laser as a light source thereof, the semiconductor laser comprises: a substrate, a first cladding layer on the substrate, an active layer on the first cladding layer, a second cladding layer on the active layer; and the second cladding layer has a plurality of steps of equivalent complex index of refraction disposed to be parallel to p-n junction direction and to be perpendicular to a cavity direction.

Semiconductor laser, optical pickup device, and optical record and/or

A semiconductor laser device having light output monitoring light-receiving portion can be fabricated monolithically. A semiconductor laser element (LD) composed of a first cladding layer (22), an active layer (23) and a second cladding layer (24) is formed on a semiconductor substrate (21). A light-receiving portion (PD.sub.1) of a pn junction is formed on the semiconductor substrate (21) disposed behind the semiconductor laser element (LD) by diffusion or selective growth.

Optical device and method of manufacturing the same

Optical device

An optical device for detecting a magneto-optical signal can be simplified and miniaturized in arrangement. An optical device for detecting a magneto-optical signal includes an optical element in which a light-emitting portion and a light receiving portion are closely disposed on a common substrate and in which reflected-back light obtained from a magneto-optical medium after light from the light-emitting portion was reflected on the magneto-optical medium is detected at a position near confocal position by the light receiving portion and another light receiving element. The reflected-back light from the magneto-optical medium is divided. One reflected-back light is detected by the light receiving portion of the optical element and the other reflected-back light is detected by another light receiving element.

Semiconductor laser device to detect a divided reflected light beam

An optical device structure can be simplified and miniaturized on the whole. A fabrication of optical device can be simplified and the optical device can be improved in reliability. The optical device can increase its output, operate a light emitting light source with a reduced power and reduce a power consumption by increasing a quantity of reflected-back light to a photosensor device, i.e., a quantity of photosensed light. An optical device includes a light emitting section (1), a radiated section (2), a converging means (3) and a photosensor section (4). Light emitted from the light emitting section (1) is converged and radiated on the radiated section (2) by the converging means (3). Reflected-back light (L.sub.R) reflected from the radiated section (2) is converged and the photosensor section (4) is disposed near a confocal of the converging means (3) concerning reflected-back light from the radiated section (2). Light emitted from the light emitting section (1) is passed through a path of the same axis and photosensed by the photosensor section (4) as shown by a one-dot chain line (a) representing the optical axis before and after the emitted light is reflected by the radiated section (2).

Optical device having a light emitter and a photosensor on the same

An optical device for detecting a magneto-optical signal can be simplified and miniaturized in arrangement. An optical device for detecting a magneto-optical signal includes an optical element (101) in which a light-emitting portion (4) and a light-receiving portion (5) are closely disposed on a common substrate and in which reflected-back light obtained from a magneto-optical medium (34) after light emitted from the light-emitting portion (4) was reflected on the magneto-optical medium (34) is detected at a position near confocal position by the light-receiving portion (5). The light-receiving portion (5) on the optical element (1) has a light-receiving surface inclined relative to the optical axis of the reflected-back light formed thereon so that the light-receiving portion has a polarization selective transmittance function on its surface. Thus, the reflected-back light from the magneto-optical medium (34) can be received and detected by the light-receiving portion (5) on the optical element (101).

Optical device for magneto-optical disc system

An optical device for detecting a magneto-optical signal can be simplified and miniaturized in arrangement. An optical device for detecting a magneto-optical signal includes an optical element in which a light-emitting portion and a light receiving portion are closely disposed on a common substrate and in which reflected-back light obtained from a magneto-optical medium after light from the light-emitting portion was reflected on the magneto-optical medium is detected at a position near confocal position by the light receiving portion and another light receiving element. The reflected-back light from the magneto-optical medium is divided. One reflected-back light is detected by the light receiving portion of the optical element 1 and the other reflected-back light is detected by another light receiving element.

A semiconductor laser and an optical device employing the semiconductor laser are described. The semiconductor laser comprises and activating layer; first and second cladding layers for sandwiching the activating layer, the energy gaps of which are greater than that of the activating layer; a current blocking layer provided in contact with both sides of the activating layer; a first electrode electrically connected to the first cladding layer; and a second electrode electrically connected to the second cladding layer. The activating layer has a structure that the activating layer is two-dimensionally confined within the first cladding layer, the second cladding layer, and the current blocking layer, reflectivity of at least on end face of a resonator of the activating layer is less than, or equal to 5%, and loss in the resonator of the activating layer is higher than, or equal to 100 cm.sup.-3.

Growing community of inventors

Kanagawa, Japan

Kenji Sahara