Mitsubishi Denki Kabushiki Kaisha

Ryoichi Hirano

Wataru Susaki

Hirofumi Namizaki

Kimio Shigihara

Toshio Tanaka

Etsuji Omura

Akira Takemoto

Hideyo Higuchi

Yasushi Sakakibara

Etsuji Oomura

Takeshi Kamizato

A monolithic semiconductor laser array includes an insulating substrate, a plurality of semiconductor layers epitaxially grown on the substrate and forming a laser structure, and at least one groove transverse to the substrate extending through the semiconductor layers into the substrate, dividing the semiconductor laser structure into at least two mutually isolated parts. Within each of the isolated parts of the semiconductor laser structure, a first groove includes a side wall transverse to the substrate and forming a first resonator facet of a semiconductor laser. A second groove in each of the parts includes a second side wall transverse to the substrate and opposite the first side wall, forming a second resonator facet of the semiconductor laser in that part. Each second groove also includes a third side wall oblique to the substrate and opposite the second side wall for reflecting light from the respective semiconductor laser so that light from each of the semiconductor lasers is emitted along a common axis transverse to the substrate. The second grooves are arranged radially about a common point on the substrate. The semiconductor lasers may be electrically connected in series to each other.

Monolithic semiconductor laser array of radially disposed lasers

A semiconductor light emitting device includes a semiconductor light emitting element mounted on a package stem via a radiating heatsink block, the light emitting point of the light emitting element being positioned on the central axis of the stem and at or near the center of mass of the heatsink block. Another light emitting device includes a light emitting element mounted on a stem via a heatsink block, the light emitting point of the element being positioned on the central axis of the stem with only a portion of a lower surface of the heatsink block close to the central axis of the stem attached to the stem. The movement of the light emitting point with temperature variations is suppressed. Another light emitting device includes a laser chip element mounted on a package stem via a heatsink block, the laser chip element being mounted on the heatsink block so that the emitted light forms an angle .theta. with a surface of the stem and the position and angle of the emitted light do not vary when the temperature changes.

Semiconductor light emitting device

A method of manufacturing a semiconductor light emitting device comprises the steps of: forming a p-InP first semiconductor layer (11) on a p-type semiconductor substrate (10) by a first growth or diffusion; forming a groove (15) shaped like a stripe in the substrate and the first semiconductor layer; and successively forming a p-InP second semiconductor layer (12), a p or n-InGaAsP third semiconductor layer (13) and an n-InP fourth semiconductor layer (14) in the regions including the inner and outer portions of the grooves by the second growth. In this manufacturing method, the carrier concentration of the p-type impurity in the first semiconductor layer is selected to be higher than the carrier concentration in the fourth semiconductor layer. As a result, by the growth process of the respective semiconductor layers in the inner and outer portions of the groove or by the heat treatment after a growth process, the impurity can be diffused from the first semiconductor layer into the fourth semiconductor layer and the p-n junction faces can be moved from the inner surfaces of the groove into the fourth semiconductor layer.

Method of manufacturing semiconductor light emitting device

In order to prevent the output characteristic of a semiconductor laser from being saturated at higher temperatures due to the thyristor effect of a combination of the semiconductor layers thereof, an intermediate layer of a conductivity type the same as that of the substrate and opposite that of the first semiconductor layer is provided between the substrate and the first layer. Due to the relatively low carrier density of the intermediate layer, oscillation can be stably carried out even at higher temperatures without triggering the thyristor structure.

Buried semiconductor laser avoiding thyristor action

A first growth melting solution which has been used for the growth of a first layer is first replaced with a third melting solution and then with a second growth melting solution for the growth of a second layer. Using the third melting solution of a composition intermediate the first and second melting solutions effectively suppresses supersaturate or unsaturation of the solute during replacement of the melting solutions.

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Itami, Japan

Ryoichi Hirano