Rohm Co., Ltd.

Jun Ichihara

Haruo Tanaka

Hironobu Sai

Ken Nakahara

Tetsuhiro Tanabe

Tomohiro Yamazaki

Hisayoshi Kitajima

Hirohisa Yano

Shuichi Nawae

A photo coupler includes a semiconductor laser, a semiconductor light-receiver, a resin protector, a reflective film, a light pipe, and electrodes. The light pipe is made of resin, has a rectangular parallelepiped shape, and is provided so as to surround an outer circumferential portion of the semiconductor light-receiver. On a center portion of an upper surface of the light pipe, a recessed portion shaped in a frustum of quadrangular pyramid tapered toward the semiconductor light-receiver is formed. The reflective film is shaped in a frustum surface of pyramid tapered toward the semiconductor light-receiver, and is formed on side surfaces of the recessed portion.

Photo coupler

An optical element and an optical transmission member are fixedly secured onto a substrate so as to be coupled to each other. In this substrate, a through hole is formed between an optical element secured portion and an optical transmission member secured portion. In an attempt to assemble these optical transmission member and optical element so as to make the coupling at an optimal position, first, the position of the optical transmission member is adjusted to an optimal position, and after measuring the position by a laser micrometer, the optical transmission member is fixedly secured thereto by using a soldering material. Thus, measurements are again carried out by the laser micrometer to detect an amount of deviation from the measured value before the securing process, and the secured portion is again fused so that the optical transmission member is shifted based on the amount of deviation, and again fixedly secured thereon.

Optical module and method for manufacturing the same

A lower multilayer reflection film (), a light emitting layer forming portion () and an upper multilayer reflection film () are sequentially formed on a substrate () to form a semiconductor laminated portion (), and a current injection region A is formed at a part of the semiconductor laminated portion so as to emit light from the surface in the center thereof. And, according to the present invention, the current injection region A is formed so as to be deflected from a center of the substrate. As a result, there is provided a surface light emitting type semiconductor laser capable of monitoring a light emitting power correctly and controlling it automatically in order to achieve the constant light emitting power in a case where the surface light emitting type laser chip is used as a light source for a pickup or the like.

Surface light emitting type semiconductor laser having a vertical cavity

On a semiconductor substrate ( ), a double hetero structure portion ( ) in which an active layer ( ) having smaller band gap is sandwiched between semiconductor layers ( ) having larger band gap than that of the active layer ( ) is formed. A light reflection film ( ) is formed at least a part of side walls of the double hetero structure portion ( ). As a result, a semiconductor light emitting device that light which leaks from side wall of light emitting area in a chip is reduced and emission light can be outputted efficiently can be obtained.

Semiconductor light emitting device and manufacturing method thereof

A light source device for a laser beam printer in which a semiconductor laser is driven with a pulse current having a minimum pulse width at the ON time on the order of milliseconds or less is provided, wherein the semiconductor laser is formed so that either the rate of change at the rise portion of the pulse current becomes &plusmn;8% or less or the semiconductor laser is excited in a multiple mode in the vicinity of the threshold value of the oscillation, and the semiconductor laser oscillates in a single mode at a current separated from the threshold value, by adjusting of at least one of the width w of a stripe groove ( ) of the current block layer, the composition of clad layers ( ), the distance d between the current block layer ( ) and the active layer ( ), the composition of the current block layer ( ) and the formation of a light absorption layer into the current block layer ( ). As a consequence, in the case where the light source device for the laser beam printer is driven with a short drive pulse on the order of several hundred micro seconds, the light source device becomes such that a transient phenomenon is not generated at the time of the rise of the pulse and a stable light output can be obtained.

Light source device for laser beam printer

An optical communication module comprises a light emitting element for generating the transmission signal, a condenser lens for connecting the transmission signal light from the light emitting element to the light transmission line, a light receiving element for receiving the receiving signal light from the light transmission line, and a package that covers the light emitting element and the light receiving element, and uses the condenser lens as an opening window, wherein the wavelength selective film for allowing the required waveband light to transmit and the unwanted waveband light to reflect is coated on the transparent member installed on or in the vicinity of the convex surface of the condenser lens. As a result, a bi-directional optical communication module of an inexpensive construction can be obtained, which can receive the desired waveband light only without using a special component such as a wave separator and does not return the unwanted waveband light to the light transmission line.

Optical communication module

An optical connector includes an elongate housing. A partition wall is formed integral with and within the housing. The partition wall is formed with a sleeve holder and an elongate hole. When an engagement member is inserted into the housing, its leg is inserted through the elongate hole. An optical module is accommodated in a case by a spring member, and the case is in turn inserted in the housing. A split sleeve of the optical module is inserted in the sleeve holder, and the engaging member is held by the partition wall and the case. When an optical fiber connector plug is inserted in the housing, a ferrule is inserted into the sleeve and coupled to a rod lens of the optical module.

Optical connector employing an optical fiber connector plug

A GaN-based compound semiconductor layer is formed on a substrate. An etch mask of a Ti film is formed on a surface of said gallium-nitride based compound semiconductor. The gallium-nitride based compound semiconductor is selectively etched through an opening of said etch mask. With this method, even where the semiconductor is difficult to etch, it is possible to efficiently etch the semiconductor vertically relative to a surface thereof by once forming a mask without troubles such as stripping-off of a mask. If the etch mask uses a metal film easy to oxidize to perform etching on the semiconductor layer while supplying an oxidizing source, the selective etch ratio can be further increased, enabling etching by a thin etch film.

Method of etching gallium-nitride based compound semiconductor layer and

Disclosed is a method of manufacturing a semiconductor laser. A wafer having a substrate having a semiconductor layer including a light-emitting forming portion epitaxially grown on a surface of the substrate is broken into laser chips having a light-emitting surface at an end face thereof. When breaking the wafer into the chips, the breaking at the light-emitting surface is carried out by first forming street grooves in the substrate and thereafter cleaving the light-emitting layer forming portion. By doing so, there is no necessity of thinning the substrate to a required extent, facilitating handling during the manufacture process. A roughened surface of the street groove is provided in the substrate underlying the light-emitting layer forming portion, which is convenient for irregular reflection of a return light beam often encountered in an optical disc pickup device.

Growing community of inventors

Kyoto, Japan

Jun Ichihara