Rohm Co., Ltd.

Tdk Corporation

Sae Magnetics (h.k.) Limited

Tsuguki Noma

Yoshito Nishioka

Yoichi Mugino

Koji Shimazawa

Minoru Akutsu

Takashi Honda

Ryuji Fujii

Yoshiteru Nagai

Kosuke Tanaka

Seiichi Takayama

Masaaki Kaneko

Satoshi Uchida

Tsutomu Ishikawa

Miroru Murayama

Yoshita Nishioka

Hosei Mitsuzawa

A semiconductor laser device capable of high output is provided. A semiconductor laser diode includes: a substrate; and a semiconductor stacked structure, which is formed on the substrate through crystal growth. The semiconductor stacked structure includes: an n-type (AlGa)InP cladding layer and a p-type (AlGa)InP cladding layer; an n-side AlGaAs guiding layer and a p-side AlGaAs guiding layer, which are sandwiched between the cladding layers; and an active layer, which is sandwiched between the guiding layers. The active layer is formed of a quantum well layer including an AlGaAsPlayer and a barrier layer including an AlGaAs layer that are alternatively repetitively stacked for a plurality of periods.

Semiconductor laser device

A semiconductor laser device includes an n-type clad layer, a first p-type clad layer and a ridge stripe. The device also includes an active layer interposed between the n-type clad layer and the first p-type clad layer, and a current-blocking layer formed on side surfaces of the ridge stripe. The ridge stripe of the device includes a second p-type clad layer formed into a ridge stripe shape on the opposite surface of the first p-type clad layer from the n-type clad layer. The ridge stripe is formed such that a first ridge width as the width of a surface of the second p-type clad layer exists on the same side as the first p-type clad layer and a second ridge width as the width of a surface of the second p-type clad layer exists on the opposite side from the first p-type clad layer.

Semiconductor laser device and manufacturing method thereof

A light source unit has a substrate, a light source that is mounted to the substrate. The light source includes; a first emission part that emits a forward light, the forward light being a laser light in an oscillation state; a second emission part that is located on a side opposite to the first emission part and that emits a rearward light, the rearward light being a laser light in an oscillation state; and a light leakage part located at a position different from the first emission part and the second emission part. The light source further includes a photodetector that is provided on the substrate, wherein the photodetector has a light receiving surface for detecting a leakage light that leaks from the light leakage part.

Light source unit, heat-assisted magnetic recording head using the same, and light source for light source unit

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

Provided is a method for performing a burn-in test on an object under test in which a plurality of electrodes are provided in positions at different heights. The method comprising steps of: preparing an object under test in which an electrode in a higher position have a higher surface roughness among the plurality of electrodes; bringing a plurality of sheet-type probes into contact with the plurality of electrodes, respectively; and supplying an electric current with the plurality of electrodes through the plurality of sheet-type probes. By implementing the method, the sheet-type probes can be kept in stable contact with the electrodes because electrodes in a higher position have a higher surface roughness Ra than electrodes in a lower position. Consequently, stable and reliable burn-in test can be performed.

Method for performing burn-in test

A semiconductor laser device includes a p-type clad layer and an n-type clad layer, a p-side guide layer and an n-side guide layer interposed between the p-type clad layer and the n-type clad layer, and an active layer interposed between the p-side guide layer and the n-side guide layer. The active layer includes at least two quantum well layers and a barrier layer interposed between the quantum well layers adjoining to each other. Each of the p-type clad layer and the n-type clad layer is formed of a (AlGa)InP layer (0&#x2266;x1&#x2266;1). Each of the p-side guide layer, the n-side guide layer and the barrier layer is formed of a AlGaAs layer (0&#x2266;x2&#x2266;1). Each of the quantum well layers is formed of a GaAsPlayer (0&#x2266;x3&#x2266;1). The (AlGa)InP layer has a composition satisfying an inequality, x1&#x3e;0.7. The AlGaAs layer has a composition satisfying an inequality, 0.4&#x2266;x2&#x2266;0.8.

A plurality of laser diode units is tested in a bar state, each of the laser diode units in which a laser diode that includes a first electrode and a second electrode formed on surfaces facing each other and that is mounted on a mounting surface of a submount such that the first electrode faces the mounting surface of the submount. The method includes preparing a bar in which mounting areas each of which includes the laser diode unit formed thereon and dicing margins for separating the bar into the separate laser diode units are alternatively aligned along a longitudinal direction wherein a first pad electrically connected with the first electrode of the laser diode is disposed on the mounting surface of each of the mounting areas of the submounts and a second pad electrically connected to the first pad of either one of the mounting areas that are adjacent to the dicing margin is disposed on the mounting surface of each of the dicing margins of the submounts: contacting sheet-shaped probes to the second electrode and the second pad at a slantwise angle with respect to the second electrode and the second pad, and pressing the probes to the second electrode and the second pad while deforming the probes; and providing a potential difference between the second electrode and the second pad through the probes so that the laser diode emits laser light.

Method of burn-in testing for thermally assisted head

A thermally assisted magnetic head includes a slider and a light source unit. The light source unit includes a semiconductor laser diode. The semiconductor laser diode includes an n-type (AlGa)InP cladding layer, a p-type (AlGa)InP cladding layer, an n-side AlGaAs guide layer placed between these cladding layers, a p-side AlGaAs guide layer placed between these cladding layers, and an active layer placed between these guide layers.

Thermally assisted magnetic head

A semiconductor laser deviceincludes infrared and red laser elementsprovided on a substrate, where the infrared elementincludes a laminate of a first lower clad layer, a first active layerand a first upper clad layer, and the red elementincludes a laminate of a second lower clad layer, a second active layerand a second upper clad layer. The clad layerincludes a third lower clad layerformed on the substrate, an etching stop layerformed on the third lower clad layer, and a fourth lower clad layerformed on the etching stop layerat a region provided with the infrared element. The second lower clad layeris formed on the etching stop layerexcept at the region of the infrared element

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Kyoto, Japan

Tsuguki Noma