Rohm Co., Ltd.

Satoshi Uchida

Hiroshi Mataki

Katsuhiko Ikawa

Hiroaki Watanabe

Yuki Tanuma

Tsuguki Noma

Masato Mushiage

Hajime Sakiyama

Norio Yoshizawa

Masayoshi Ashida

Kaoru Kusunoki

Tsutomu Ishikawa

Hiroaki Takuma

Takeyuki Adachi

Miroru Murayama

A light-emitting module is provided with a light-emitting element, a base, and a wiring pattern. The base includes an installation surface facing in a first direction and a mounting surface facing in a second direction which is at right angles to the first direction. The light-emitting element is installed on the installation surface. The wiring pattern is formed on the base and is in electrical contact with the light-emitting element. The base includes a pair of mounting recesses recessed from the mounting surface and spaced from each other in a third direction which is at right angles to both the first direction and the second direction. The wiring pattern includes a pair of mounting-surface electrodes respectively covering at least a part of the pair of mounting recesses.

Light-emitting module, light-emitting device and method of making light-emitting module

Provided is a semiconductor laser which has a low operating current and stably oscillates even for high-temperature output. The semiconductor laser is provided with a substrate (); an n-type clad layer () arranged on the substrate (); an active layer () arranged on the n-type clad layer (); a p-type clad layer (), which is arranged on the active layer () and composed of a compound containing Al and has a stripe-shaped ridge structure to be a current channel; a current block layer (), which is arranged on the surface of the p-clad layer () excluding an upper surface of the ridge structure and composed of a compound containing Al and has an Al composition ratio not more than that of the p-type clad layer (); and a light absorption layer (), which is arranged on the current block layer () and absorbs light at the laser oscillation wavelength.

Semiconductor laser

A semiconductor laser element is made by forming a lower clad layer, an active layer and an upper clad layer sequentially one on top of another on a semiconductor substrate, forming an etching stop layer completely over the upper clad layer, forming a contact layer on the etching stop layer, and etching portions of the contact layer to form steps. The etching stop layer has a slower etching speed than the contact layer against the etching liquid used for forming the steps by etching portions of the contact layer. An upper electrode is formed on the contact layer and a lower electrode is formed on the bottom surface of the substrate. The steps provide areas in the active layer where a current will not flow through.

Semiconductor laser elements and method of making same

A semiconductor laser device has a semiconductor laser element placed inside a package on an electrically conductive submount such that one of the electrodes with one conduction type sandwiching its p-n junction is electrically connected to it. The submount is placed on a metallic heat sink, separated therefrom by a layer of an electrical insulator having a larger thermal conductivity than the submount. The other electrode of the laser element (of the opposite conduction type) is electrically connected to the heat sink, and one of externally extending lead pins is electrically connected to the submount. According to a preferred embodiment, the other electrode of the laser element is electrically connected instead to one of the lead pins and the submount is electrically connected instead to another of the lead pins. Thus, the capacitance of the submount and the inductance of the package will be in an electrically floating condition when the laser device is activated, and the device is adapted for high-frequency operations.

Semiconductor laser devices

Fabrication of a semiconductor laser having a double hetero junction structure including: an active layer; cladding layers including an upper layer and a lower layer, the cladding layers sandwiching the active layer; and a current blocking layer including a stripe recess for acting as a current passage. The current blocking layer is provided within at least one of the cladding layers. The current blocking layer includes a plurality of layers, at least one layer of the layers having a slit therein extending transversely to the stripe recess.

Semiconductor laser and manufacturing method therefor

A semiconductor laser having a double hetero junction structure including: an active layer; cladding layers including an upper layer and a lower layer, the cladding layers sandwiching the active layer; and a current blocking layer including a stripe recess for acting as a current passage. The current blocking layer is provided within at least one of the cladding layers. The current blocking layer comprises a plurality of layers, at least one layer of the layers having a slit therein extending transversely to the stripe recess.

A semiconductor laser includes an active layer having a light-emitting region of striped structure. A cladding layer is formed on the active layer. Another cladding layer is formed under the active layer. The active layer is interposed between the cladding layer and the another cladding layer. Facets are formed on both ends of a stripe of the light-emitting region in which a part of light emitted radiated, and the remaining light is reflected and amplified. The semiconductor laser includes a means for having a minimum value of a coherence in a range between 2 mW and 7 mW of output of a light radiated from one of the facets which is a light output, and for preventing a phenomenon in which the output is reduced in a range at most 25 mW in accordance with an increase of the current, varied by a variation of a current applied to the active layer.

Semiconductor laser and method for manufacturing the same

The present invention provides a sub-mount type device for emitting light which has high speed response and yet can radiate heat sufficiently. The sub-mount type device for emitting light comprises a heat sink (4), a sub-mount body (62) mounted on the heat sink (4) which comprises an insulating layer (38) with a upper face and a lower face, a upper electrode (42) on the upper face and a lower electrode 44 and 36 on the lower face, the insulating layer having two parts of the insulating layer (38) thickness of which is different, and a chip (30) for emitting light above the thinner part (39) of the insulating layer (38).

Sub-mount type device for emitting light

A method for selecting a semiconductor laser is provided which contributes to improved productivity of a highly reliable semiconductor laser of prolonged lifetime, and which includes the steps of: (a) measuring highest peak intensity, Ia, and next highest peak intensity, Ib, of an interference fringes pattern of laser radiation of each semiconductor laser using an interferometer to find a damping ratio of visibility of the interference fringes pattern, .gamma.=Ib/Ia; and (b) selecting a semiconductor exhibiting self-pulsation by selecting a semiconductor laser which emits laser radiation whose damping ratio of visibility, .gamma., is 0.5 or less.

Method for selecting a self pulsating semiconductor laser

A semiconductor laser chip comprises a substrate and material layers successively formed on the substrate. The laser chip has an output cleavage face and emits an output laser beam which is inclined to the output cleavage face. The laser chip may be incorporated in a laser pickup device for optically reading information from an optical data carrier such as optical disk.

Semiconductor laser device which emits inclined laser beam

A self-aligned type, high-power semiconductor laser is provided which exhibits multi-longitudinal mode oscillation in the low-power operation (at a light power output of, for example, 3 mW) through it is of a refractive index guiding structure capable of single transverse mode oscillation in up to the high-power operation. Specifically, the semiconductor laser is of an AlGaAs system and has a waveguide mechanism resulting from complex refractive index, and wherein a current-blocking layer is 2000 to 6000 .ANG. thick.

A semiconductor laser device comprises: an active layer; a lower clad layer provided below the active layer; an upper clad layer provided above the active layer; and a current blocking layer, provided above the upper clad layer, for limiting an active region of the active layer in a direction along a width to make the active region of a striped form which has a wide portion and a narrow portion. According to the device, coherence of an oscillated laser beam is reduced, thereby to decrease a feedback induced noise when used for a pickup of an optical information recording/reproducing apparatus.

Growing community of inventors

Kyoto, Japan

Satoshi Uchida