Matsushita Electric Industrial Co., Ltd.

Matsushita Electronics Corporation

Ken Hamada

Kunio Itoh

Hirokazu Shimizu

Masahiro Kume

Masaru Wada

Takao Shibutani

Hideyuki Nakanishi

Iwao Teramoto

Masuru Wada

Fumiko Tajiri

A deflection plate for deflecting laser beams includes a transparent plate on which two grating areas are formed on the same surface. The first grating area has a plurality of parallel grooves. The second grating area has a plurality of grooves in a predetermined pattern. The depth and/or the duty ratio of the grooves in the first grating area differs from that in the second grating area.

Deflection plate for optical pick-up device

A BTRS (buried Twin-Ridge Substrate) structure laser, wherein an oblong protrusion (10) is provided on a substrate (1) of a first conductivity type and two ridges (9, 9) divided by a groove (31) therebetween are provided on a second layer (2) of a second conductivity type, and thereon plural layers (3, 4, 5, 6) including an active layer (4) are provided is improved to have longer service life such that: the protrusion (10) is shortened so as to have its both ends apart inside cavity facet of the substrate (1), or further by width of each ridge (9, 9) is narrowed at both ends thereof thereby forming narrowed end parts (9', 9'), so that excessive current injection to the active layer near the cavity facet is eliminated.

Buried twin ridge substrate laser

In a TRS (twin ridge substrate) type semiconductor laser, reflectivity at both facets of the resonator at the oscillation wavelength is selected to be higher than the reflectivity of the semiconductor crystal of the laser device, but smaller than 1, thereby stabilizing the light oscillation with a low S/N ratio.

Semiconductor laser device with decreased light intensity noise

A semiconductor substrate having a groove with a dove-tail-shaped cross section is used as a substrate and thereon, several epitaxial layers including an active layer are formed and a current injection region is formed immediately above the groove; the semiconductor laser attains a high power lasing with the fundamental transverse mode.

A high-output semiconductor laser of dove tail groove type

The invention provides a chemical etching method for a semiconductor device, which comprises a step of forming a first layer of Ga.sub.1-x Al.sub.x As (0.ltoreq.x&lt;1) having a surface (100), a step of forming on the first layer a second layer of Ga.sub.1-y Al.sub.y As (0.ltoreq.y&lt;1) having a surface (100), and a step of chemically etching the layers from a level above the second layer and along the direction of &lt;011&gt;. The slope angle of etch face of the second layer depends on the mol fraction y of the second layer, and the slope angle of etch face of the first layer depends on the mol fraction y of the second layer and the mol fraction x of the first layer. These facts are best utilized in the invention so that the etch profile of the first layer may have a desired slope angle. By utilizing this chemical etching method it is possible to produce by chemical etching a semiconductor laser having a flat cavity facet perpendicular to a junction; it is also possible to provide an inner stripe type semiconductor laser having grooves whose side walls are perpendicular.

Growing community of inventors

Toyonaka, Japan

Ken Hamada