Nippon Electric Co., Ltd.

Nippon Selfoc Co., Ltd.

Izuo Hayashi

Hiroo Yonezu

Yasuo Nannichi

Masayasu Ueno

Isamu Sakuma

Roy Lang

Katsuhiko Nishida

Tonao Yuasa

Takao Furruse

Taibun Kamejima

Toshio Uji

A semiconductor laser having a double heterostructure configuration is provided with a light waveguide layer extending between a pair of mirrors. A thin active layer is disposed adjacent to the waveguide layer, and is formed in the shape of a stripe having a width of approximately 5 .mu.m. The stripe is shorter in axial length than the waveguide, such that the ends of the stripe are spaced from the mirrors by a distance of 30 to 60 .mu.m.

Injection-type semiconductor laser

In a stripe geometry buried double heterostructure semiconductor laser device, a first semiconductor layer for effecting laser oscillation upon injection of carriers is sandwiched between second and third semiconductor layers having a wider band gap than the first semiconductor layer. This double heterostructure is partially rendered mesashaped to provide a stripe geometry, and the vacancy resulting from mesa formation is filled with a fourth semiconductor layer having a wider band gap than the first semiconductor layer. In this invention, the region of the first semiconductor layer which is spaced from both end facets of the device by a distance at least equal to the diffusion length of carriers has a narrower band gap that the other regions of the first semiconductor layer.

Semiconductor laser device

In an active layer restricted by a pair of heterojunctions in a semiconductor laser, a stripe region and a contiguous region are made to have a difference in kinds and/or concentrations of impurity to give the stripe region a higher dielectric constant, preferably by about 0.01-1%, than the contiguous region whereby transverse laser oscillation confined to the active layer by the heterojunctions is further confined to the stripe region in a width direction parallel to the heterojunctions. The dielectric constant profile established in the active layer stabilizes the transverse mode and eliminates nonlinearities in the laser output - exciting current curve as well as other undesirable performance characteristics that are exhibited in conventional stripe-geometry lasers. The difference in the impurity gives the stripe region a narrower band gap of from about 5 to about 100 meV than the contiguous region. For a laser of III-V-Group semiconductor materials, the difference is achieved by doping these regions with an n-type and/or a p-type impurity. The stripe width may be between about 1 micron and several tens of microns. The laser stably produces a single-mode optical output of 10 and 30 mW or more in CW and pulsed operation, respectively.

Heterostructure laser having a stripe region defined in an active layer

A semiconductor laser device in which at least one of the main surfaces of a semiconductor laser crystal body which generates heat during operation is brought into thermal contact with a silicon crystal heat-sink body.

Semiconductor laser device equipped with a silicon heat sink

A hermetically sealed injection semiconductor laser device includes a hollow cylinder in which a crystal laser pellet is enclosed. The ends of the cylinder are sealed by metal electrodes one of which projects axially into the cylinder and is connected to an electrode surface of the crystal pellet. A lens element is disposed within the cylinder.

Hermetically-sealed injection semiconductor laser device

A strip-geometry semiconductor double-heterostructure laser device includes an n-GaAs substrate on which a first layer of n-Al.sub.x Ga.sub.1-x As and a second layer of p-AlyGa.sub.1-y As are formed by epitaxial growth techniques. A third layer of heat- and Ga melt resistant material of narrow stripe geometry is formed on the second layer. After the second layer and part of the first layer, except for their stripe portions, are meltbacked by Ga melt liquid, a fourth layer of n-Al.sub.z Ga.sub.1-z As is formed by epitaxial growth techniques of the same Ga melt liquid in one process.

Growing community of inventors

Tokyo, Japan

Izuo Hayashi