Sharp Kabushiki Kaisha Corporation

Sanyo Electric Co., Ltd.

Yukio Yamasaki

Shigetoshi Ito

Toshiyuki Kawakami

Mototaka Taneya

Susumu Omi

Yuhzoh Tsuda

Tomoki Ono

Toshiyuki Okumura

Takayuki Yuasa

Kei Yamamoto

Shuichiro Yamamoto

A method of producing a nitride semiconductor laser device includes: forming a wafer including a nitride semiconductor layer of a first conductivity type, an active layer of a nitride semiconductor, a nitride semiconductor layer of a second conductivity type, and an electrode pad for the second conductivity type stacked in this order on a main surface of a conductive substrate and also including stripe-like waveguide structures parallel to the active layer; cutting the wafer to obtain a first type and a second type of laser device chips; and distinguishing between the first type and the second type of chips by automatic image recognition. The first type and the second type of chips are different from each other in position of the stripe-like waveguide structure with respect to a width direction of each chip and also in area ratio of the electrode pad to the main surface of the substrate.

Nitride semiconductor laser device and method of producing the same

A method of producing a nitride semiconductor laser device includes forming a wafer including a nitride semiconductor layer of a first conductivity type, an active layer of a nitride semiconductor, a nitride semiconductor layer of a second conductivity type, and an electrode pad for the second conductivity type stacked in this order on a main surface of a conductive substrate and also including stripe-like waveguide structures parallel to the active layer; cutting the wafer to obtain a first type and a second type of laser device chips; and distinguishing between the first type and the second type of chips by automatic image recognition. The first type and the second type of chips are different from each other in position of the stripe-like waveguide structure with respect to a width direction of each chip and also in area ratio of the electrode pad to the main surface of the substrate.

The present invention relates to a nitride semiconductor laser device having a structure in which two or more of nitride semiconductor laser elements, having at least a first electrode on a first main surface of a first conductive type conductive substrate, having at least a first conductive type nitride semiconductor layer, an active layer, a second conductive type nitride semiconductor layer, and a second electrode on a second main surface of the conductive substrate, and having a stripe-waveguide structure parallel to the first main surface, are arranged in a direction parallel to the first main surface and a direction perpendicular to the direction of light that is emitted from the stripe waveguide structure in the nitride semiconductor laser device, and the first sub-mount and the first electrode of the nitride semiconductor laser element are electrically and heat-conductively connected, and the second sub-mount and the second electrode of the nitride semiconductor laser element are electrically and heat-conductively connected.

Nitride semiconductor laser device

At each side of a ridge stripe, a trench is formed as a region carved relative to a wafer surface so that, at the time of cleaving, a surface irregularity that develops at a mirror facet near an active layer is prevented from reaching the ridge stripe

Nitride semiconductor laser element and fabrication method thereof

A semiconductor laser device having a waveguide constructed in a stack of layers including, on a substrate that is transparent and has a refractive index nfor laser light, a first clad layer of a refractive index n, a second clad layer of a refractive index n, a third clad layer of a refractive index n, a first conductivity type guide layer of a refractive index n, an active quantum well layer, a second conductivity type guide layer, a second conductivity type clad layer, and a second conductivity type contact layer deposited in that order, wherein the waveguide has an effective refractive index n, and the relationship n&#x3c;(n, n)&#x3c;n&#x3c;(n, n) is satisfied.

Semiconductor laser device

A semiconductor laser device that offers higher coupling efficiency to a pickup optical system by dramatically reducing the amount of difference between the shape of an FFP in the vertical direction and a Gaussian shape, and that can be produced at lower cost by reducing the operating power needed. The semiconductor laser device is provided with a negative electrode, a GaN substrate, a first n-type clad layer, an n-type light shielding layer that shields light, a second n-type clad layer, an n-type optical waveguide layer, a first carrier stop layer, an active layer, a second carrier stop layer, a p-type optical waveguide layer, a p-type clad layer, a p-type contact layer, and a positive electrode laid in this order.

Semiconductor laser device and optical information recording apparatus provided therewith

A drive current is generated by mixing a pulse signal from a pulse generator and a DC current from a DC current power supply using a T circuit and injected into a nitride semiconductor laser having a horizontal light-confinement ridge structure. The horizontal light-confinement coefficient of the nitride semiconductor laser is between 85% and 99%. The time when the current waveform of the drive current is continuously over the threshold current of the nitride semiconductor laser ranges from 5 nsec to 1,000 nsec.

Nitride semiconductor laser device and semiconductor optical device

A semiconductor laser device having a waveguide constructed in a stack of layers including, on a substrate transparent and having a refractive index nfor laser light, a first clad layer of a refractive index n, a second clad layer of a refractive index n, a third clad layer of a refractive index n, a first conductivity type guide layer of a refractive index n, an active quantum well layer, a second conductivity type guide layer, a second conductivity type clad layer, and a second conductivity type contact layer deposited in this order, wherein the waveguide has an effective refractive index n, and a relationship of n&#x3c;(n, n)&#x3c;n&#x3c;(n, n) is satisfied.

According to an aspect of the present invention, a nitride semiconductor laser device includes a nitride semiconductor active layer, and a stripe-shaped waveguide for guiding light generated in the active layer. At least one pair of light-absorbing films are provided in at least local regions on the opposite sides of the stripe-shaped waveguide, to reach a distance within 0.3 &#x3bc;m from the waveguide. According to another aspect of the present invention, a gan-based semiconductor laser device includes first conductivity type semiconductor layers, a semiconductor active layer and second conductivity type semiconductor layers stacked sequentially. The laser device further includes a ridge stripe provided to cause a refractive index difference for confinement of light in a lateral direction crossing a longitudinal direction of a cavity, and a current-introducing window portion provided on the ridge stripe. The current-introducing window portion includes a narrow portion that is locally narrowed compared to the width of the ridge stripe.

GaN-based semiconductor laser device

A semiconductor laser element has the following structure. In the clad layer, a difference in a light radiation loss between the basic horizontal-lateral mode and the 1st-order horizontal-lateral mode is 10 cmor more. The refractive index of the clad layer is below an effective index against light in the basic horizontal-lateral mode, and the refractive index of the clad layer is equal to or more than an effective index against light in the 1st-order horizontal-lateral mode. The upper clad layer is provided only above a portion of the active layer, and thus is at least included in the ridge-stripe structure. This structure inhibits the I-L characteristic from suffering kink and realizes oscillations in the basic horizontal-lateral mode until output power reaches as high as 60&#x2013;100 mW, in a peak output power of the semiconductor laser element at the time of a pulse current operation. This structure also enables the FFP to have an ellipticity of close to 1, thus making the spot of the semiconductor laser element close to a circular shape.

Semiconductor laser element and optical data recording device

In a wafer having an LD structureformed on a GaN-based substrate, cleavage guide groovesare formed in its surface by scribing from above the LD structurewith a diamond needle. The cleavage guide groovesare formed one along each of stripe-shaped waveguidesformed parallel to the &#x3c;1-100&#x3e; direction of the wafer, and are formed in the shape of broken lines in the &#x3c;11-20&#x3e; direction of the wafer.

Method of fabricating nitride semiconductor device

A nitride semiconductor light emitting device includes a processed substrate () including a groove and a hill formed on a main surface of a nitride semiconductor substrate, a nitride semiconductor underlayer () covering the groove and the hill of the processed substrate, and a light emitting device structure having a light emitting layer () including a quantum well layer or a quantum well layer and a barrier layer in contact with the quantum well layer between an n type layer () and a p type layer () over the nitride semiconductor underlayer. A current-constricting portion of the light emitting device structure is formed above a region more than 1 &#x3bc;m away from the center of the groove in the width direction and more than 1 &#x3bc;m away from the center of the hill in the width direction.

Nitride semiconductor laser element and optical device containing it

A nitride semiconductor laser device includes a first-conductivity-type cladding layer formed of a nitride semiconductor material; an active layer formed of a nitride semiconductor material; and a second-conductivity-type cladding layer formed of a nitride semiconductor material. The first-conductivity-type cladding layer has a first main surface and a second main surface, the first main surfaces being closer to the active layer from the second main surface, and includes a first-conductivity-type first cladding layer and a first-conductivity-type second cladding layer having a different composition from that of the first-conductivity-type first cladding layer, which are provided in this order from the first main surface. The first-conductivity-type first cladding layer has a refractive index lower than that of the first-conductivity-type second cladding layer.

Nitride semiconductor laser device and optical information reproduction apparatus using the same

In connection with a nitride semiconductor laser device optimal for example for optical pickup and an optical information reproduction apparatus having superior condensation characteristics, the semiconductor laser device includes a substrate of nitride semiconductor, a lower clad layer of nitride semiconductor stacked thereon, an active layer stacked thereon, an upper clad layer of nitride semiconductor stacked thereon, and a contact layer of AlInGaN stacked thereon having a lattice constant larger than the substrate of nitride semiconductor, and the device is cleaved and thus divided to have a surface serving as a resonator mirror.

Growing community of inventors

Daito, Japan

Yukio Yamasaki