Sharp Kabushiki Kaisha Corporation

Eastman-kodak Company

501 Sharp Kabushiki Kaisha

Toshiro Hayakawa

Takahiro Suyama

Saburo Yamamoto

Masafumi Kondo

Kohsei Takahashi

Kosei Takahashi

Seiki Yano

Nobuyuki Miyauchi

Mototaka Taneya

Sadayoshi Matsui

Mitsuhiro Matsumoto

Kazuaki Sasaki

Hiroyuki Hosoba

Masahiro Hosoda

A high-power laser diode that has a wide emitting aperture and good stability to external perturbations. Structurally, the laser diode includes an array of independently-operating narrow stripe single-mode lasers coupled at each end to a single wide stripe region having a width of 30 .mu.m or more in an arrangement which minimizes phase locking.

Stripe-type laser diode used as a light source

A high efficiency laser diode that has a narrow beam divergence in a direction perpendicular with respect to the substrate, and a low threshold current.

Laser diode

A strained quantum well laser diode in which higher reliability is achieved by reducing the degrading effects of stress. By using an active layer orientation that is equal or close to (111), it is possible to suppress degradation caused by stress, which acts in a direction parallel to the quantum well layer.

Strained quantum well laser diode

Narrow beam divergence laser diode

A method of fabricating light emitting diode array devices is provided, said method comprising the steps of layering through crystal growth the second semiconductor layer with an impurity serving as the diffusion source on the first semiconductor layer, removing by etching the area of said second semiconductor layer other than the island-like area at the location corresponding to the location where light emitting diodes are to be formed, and diffusing said impurity on said first semiconductor layer from said island-like area as the diffusion source. According to this method, such complicated process as gaseous phase diffusion, depositing ZnO film as the diffusion source, etc. may be eliminated.

Method of producing a light emitting diode array device

A light-emitting diode array is fabricated by forming a light-emitting diode heterojunction at the interface between a superlattice layer comprised of alternations of a multiplicity of semiconductor layers that have different energy gaps, and a doped diffusion mixed region having a larger energy gap than that of the superlattice layer which is formed by impurity doping of part of the said superlattice layer. The light-emitting diode array thus formed exhibits low optical crosstalk and good diode uniformity.

Heterojunction light-emitting diode array

A laser diode with a wide gain region (active layer) in which the side faces of the layers defining the gain region width are corrugated to suppress non-Fabry-Perot mode laser frequencies by scattering the light produced by stimulated emission.

Wide gain region laser diode

An optical head apparatus for optical disks has a recording and reading laser beam generator and a wavelength reducer including reducing the wavelength of light from the laser generator. The laser beam generator is a separate unit from the head slider portion, the two being connected by an optical fiber which is used to transmit the recording and reading laser light to the slider. This arrangement enables short-wavelength laser light below 550 nm to be used for writing and reading operations without increasing the weight of the slider, thereby offering high-speed access and high recording densities.

Optical head apparatus for optical disks

A semiconductor laser device is disclosed which comprises a semiconductor substrate and a multi-layered crystal structure disposed on the substrate, the multi-layered crystal structure containing a first cladding layer, a quantum-well active layer for laser oscillation, and a second cladding layer with a striped ridge portion for current injection, wherein the difference in the effective refractive index between the region underneath the striped ridge portion and the adjacent regions thereto is greater in the vicinity of at least one of the facets than inside of the facets.

Semiconductor laser device

A heterojunction type light-emitting diode array in which a carrier barrier layer is provided on the emission layer to prevent the diffusion of carriers injected from the junction side of the component light-emitting diodes. An absorption layer is provided on the carrier barrier, which also connects the light-emitting diodes, suppressing crosstalk between adjacent light-emitting elements. The array thus configured provides good emission efficiency and high uniformity.

Crosstalk preventing laser diode array

An optical semiconductor device is disclosed that comprises a quantum-well structure as an active region and exhibits a nonlinear optical effect with regard to light of energy near the band gap between the allowed band edges in the active region. The quantum-well structure of this device is composed of alternate layers consisting of at least one first semiconductor layer with a thickness smaller than the de Broglie wavelength of carriers and at least two second semiconductor layers with a band gap greater than that of the first semiconductor layer, the alternate layers being formed along a crystal orientation in the zinc-blende structure. The second semiconductor layers mentioned above are of an indirect transition type.

Optical semiconductor device

A semiconductor apparatus comprises a step-shaped substrate and a multiple-layered crystal structure formed on the substrate, said multiple-layered crystal structure is of a superlatticed layer which is composed of alternate layers consisting of plural thin layers grown by molecular beam epitaxy.

Semiconductor apparatus

A semiconductor light-emitting device is provided with optical guide layers that include at least part of compositionally graded layers provided adjacent to the light-emitting layer, and at least one end of the compositionally graded layers is provided with a bridging layer wherein the first derivative of each composition profile with respect to the layer thickness is continuous. This provides an extremely smooth change of composition from one layer to the next, and eliminates problems such as overshoot and undershoot, and can be accomplished using a general control system based on PID.

Semiconductor light-emitting devices

A semiconductor laser device comprising a substrate of a first conductivity type having a mesa; a first semiconductor layer of a second conductivity type which is formed on the upper surface of the substrate other than the mesa to form a flat plane including the top face of the mesa; a laser oscillation region which is formed on the flat plane and includes an active area for laser oscillation; and a multi-layer structure burying the laser oscillation region, the multi-layer structure comprising a high resistance layer formed on the first semiconductor layer and burying both sides of the laser oscillation region, and a second semiconductor layer of the first conductivity type formed on the high resistance layer.

A semiconductor laser device containing a laser oscillation-operating area which comprises a Ga.sub.1-x Al.sub.x As (0.ltoreq.x.ltoreq.1) quantum well active layer, Ga.sub.1-y Al.sub.y As optical guiding layers interposing the quantum well active layer therebetween, and Ga.sub.1-z Al.sub.z As cladding layers superposed on the optical guiding layers, respectively, wherein the AlAs mole fraction y at the area of each of the optical guiding layers positioned in the vicinity of the interface of the optical guiding layers and the quantum well active layer meets the relationships y-z.gtoreq.0.3 and z-y.ltoreq.0.25.

Growing community of inventors

Nara, Japan

Toshiro Hayakawa