Fuji Photo Film Company, Limited

Fujifilm Corporation

Mitsugu Wada

Toshiaki Fukunaga

Kenji Matsumoto

Toshiro Hayakawa

Toshiaki Kuniyasu

Yoshinori Hotta

Hideki Asano

Fujio Akinaga

An exposure system is provided with an exposure head formed of a red organic EL element which emits light in a red region and another organic EL element which emits light in a predetermined wavelength range shorter than the red region. The exposure system exposes a color photosensitive body containing therein at least a red silver-salt photosensitive material sensitive to the light in the red region and another silver-salt photosensitive material sensitive to the light in the predetermined wavelength range. An optical filter cuts the wavelength components which are shorter than the predetermined wavelength range and included in a sensitive range of the red silver-salt photosensitive material.

Exposure system

A semiconductor laser device having an active region including alternating layers of at least one quantum well layer and a plurality of barrier layers, where two of the plurality of barrier layers are the outermost layers of the alternating layers. Each of the at least one quantum well layer has a compressive strain, and each of the plurality of barrier layers has a tensile strain. In the active region, a strain buffer layer having an intermediate strain is formed between each quantum well layer and each of two barrier layers adjacent to the quantum well layer. Interfacial strain is thus reduced, improving high-output-power characteristics.

Semiconductor laser device having strain buffer layer between compressive-strain quantum well layer and tensile-strain barrier layer

A semiconductor laser has an active region which includes at least a quantum well layer and upper and lower optical waveguide layers and is of InGaAsP(0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1). Upper and lower AlGaAs cladding layers are formed on opposite sides of the active region. At least one of the optical waveguide layers is not smaller than 0.25 &#x3bc;m in thickness, and a part of the upper cladding layer on the upper optical waveguide layer is selectively removed up to the interface of the upper cladding layer and the upper optical waveguide layer.

Semiconductor laser and method of manufacturing the same

In a process for producing a substrate for use in a semiconductor element: a first GaN layer having a plurality of pits at its upper surface is formed; and then a second GaN layer is formed by growing a GaN crystal over the first GaN layer until the upper surface of the second GaN layer becomes flattened. Each of the above plurality of pits has an opening area of 0.005 to 100 &mgr;m and a depth of 0.1 to 10.0 &mgr;m.

GaN substrate formed under controlled growth condition over GaN layer having discretely formed pits

In a process for producing a substrate for use in a semiconductor element: a porous anodic alumina film having a great number of minute pores is formed on a surface of a base substrate; the surface of the base substrate is etched by using the porous anodic alumina film as a mask so as to form a great number of pits on the surface of the base substrate; the porous anodic alumina film is removed; and a GaN layer is formed on the surface of the base substrate by crystal growth.

Substrate including wide low-defect region for use in semiconductor element

In a semiconductor laser device including an active region which is made of an aluminum-free material and a plurality of cladding layers made of at least one AlGaAs or AlGaInP material, the active region includes a quantum well layer and at least one optical waveguide layer; a portion of the at least one optical waveguide layer located on one side of the quantum well layer has a thickness of 0.25 &mgr;m or more; and the at least one optical waveguide layer, other than a portion of the at least one optical waveguide layer being located near the quantum well layer and having a thickness of at least 10 nm, is doped with impurity of 10 cm or more.

Semiconductor laser device having thickened impurity-doped aluminum-free optical waveguide layers

In a semiconductor-laser device: an n-type cladding layer, an optical-waveguide layer, an In Ga As P compressive-strain quantum-well active layer (0<x3&lE;0.4, 0&lE;y3&lE;0.1), an optical-waveguide layer, a p-In Ga P etching-stop layer (0&lE;x6&lE;1), a p-In Ga As P etching-stop layer (0&lE;x1&lE;0.4, 0&lE;y1&lE;0.5), a p-In Ga P layer (x&equals;0.49&plusmn;0.01), and an n-In Ga P current-confinement layer are formed on an n-GaAs substrate. A stripe groove is formed down to the depth of the upper surface of the p-In Ga P etching-stop layer. A p-In Ga As P cladding layer (x4&equals;0.49y4&plusmn;0.01, x&minus;0.04&lE;x4&lE;x&minus;0.01) is formed over the current-confinement layer and the stripe groove. A p-type contact layer is formed on the p-In Ga As P cladding layer. The absolute value of the product of the strain and the thickness of the active layer does not exceed 0.25 nm, and each of the above layers other than the active layer and the etching-stop layers lattice-matches with GaAs.

High-power semiconductor laser device having current confinement structure and index-guided structure and stably oscillating in single mode

In a semiconductor laser device, a lower cladding layer, a lower optical waveguide layer, an active layer, an upper optical waveguide layer, an upper cladding layer, and a contact layer are formed in this order on a GaAs substrate. The semiconductor laser device has at least one of first and second resistance reduction layers. The first resistance reduction layer is arranged between the substrate and the lower cladding layer, and made of an InGaAsP material having an energy gap which is greater than the energy gap of the substrate, and smaller than the energy gap of the lower cladding layer. The second resistance reduction layer is arranged between the upper cladding layer and the contact layer, and made of an InGaAsP material having an energy gap which is greater than the energy gap of the contact layer, and smaller than the energy gap of the upper cladding layer.

High-power semiconductor laser device including resistance reduction layer which has intermediate energy gap

A semiconductor laser element capable of reducing an element resistance and producing a beam of high quality includes: an n-Ga Al N composition gradient layer provided between an n-GaN contact layer and an n-Ga Al N/GaN superlattice clad layer; an n-Ga Al N composition gradient layer provided between the n-Ga Al N/GaN superlattice clad layer and an n- or i-Ga Al N optical waveguide layer; a p-Ga Al N composition gradient layer provided between a p- or i-Ga Al N optical waveguide layer and a p-Ga Al N superlattice gradient layer; and a p-Ga Al N composition gradient layer provided between a p-Ga Al N/GaN superlattice upper clad layer and a p-GaN contact layer. Z4 of the n-Ga Al N composition gradient layer is continuously changed from 0 to a composition corresponding to the band gap of the Ga Al N/GaN superlattice clad layer. Z5 in the Ga Al N composition gradient layer is continuously changed from z2 to a composition corresponding to the band gap of the Ga Al N/GaN superlattice clad layer.

Semiconductor laser element

In a semiconductor laser device: a lower cladding layer; a lower optical waveguide layer; a compressive strain quantum well active layer made of In Ga As P , where 0<x3&lE;0.4, 0&lE;y3&lE;0.1; an upper optical waveguide layer; a first upper cladding layer made of In Ga P of a second conductive type, and formed on the upper optical waveguide layer; an etching stop layer made of In Ga As P of the second conductive type, where 0&lE;x1&lE;0.3, 0&lE;y1&lE;0.3; a current confinement layer made of In Ga P of the first conductive type, where x8&equals;0.49&plusmn;0.01; a second upper cladding layer made of Al Ga As of the second conductive type, where 0.20&lE;z4&lE;0.50; and a contact layer of the second conductive type are formed on a GaAs substrate of a first conductive type in this order. In the semiconductor laser device, the absolute value of the product of the strain and the thickness of the compressive strain quantum well active layer is equal to or smaller than 0.25 nm; the absolute value of a second product of the strain and the thickness of the etching stop layer is equal to or smaller than 0.25 nm; and each of the lower cladding layer, the lower optical waveguide layer, the upper optical waveguide layer, the first upper cladding layer, the current confinement layer, the second upper cladding layer, and the contact layer has such a composition as to lattice-match with the GaAs substrate.

High-power semiconductor laser device having current confinement structure and index-guided structure, and oscillating in transverse mode

In a semiconductor laser device: an n-type lower cladding layer; a lower optical waveguide layer; a compressive strain quantum well active layer made of In Ga As P , where 0<x &lE;0.4 and 0&lE;y &lE;0.1; an upper optical waveguide layer; a p-type In Ga P first upper cladding layer; an etching stop layer made of In Ga As P , where 0&lE;x &lE;0.3 and 0&lE;y &lE;0.6; an n-type In Ga P current confinement layer; a p-type second upper cladding layer made of In Ga As P , where x &equals;(0.49&plusmn;0.01)y and 0.4&lE;x &lE;0.46; and a p-type contact layer are formed on an n-type GaAs substrate in this order. At least the current confinement layer has a stripe-shape opening realizing a current injection window filled with the second upper cladding layer. The absolute value of the product of the strain and the thickness of the compressive strain quantum well active layer is equal to or smaller than 0.25 nm; the absolute value of the product of the strain and the thickness of the etching stop layer is equal to or smaller than 0.25 nm; and each of the lower cladding layer, the lower optical waveguide layer, the upper optical waveguide layer, the first upper cladding layer, the current confinement layer, the second upper cladding layer, and the contact layer has such a composition as to lattice-match with the GaAs substrate.

High-power semiconductor laser device having current confinement structure and index-guided structure

A semiconductor laser includes a first clad layer having one of p-type conductivity and n-type conductivity, a first optical waveguide layer, a first barrier layer of GaAs,P,, a quantum-well active layer of In,Ga,As,P,, a second barrier layer of GaAs,P,, a second optical waveguide layer and a second clad layer having the of p-type conductivity and n-type conductivity formed in this order on a GaAs substrate. Each of the first and second clad layers is of a composition which matches with the GaAs substrate in lattice. Each of the first and second optical waveguide layers is of a InGaAsP composition which matches with the GaAs substrate in lattice. Each of the first and second barrier layers is 10 to 30 nm in thickness and is of a composition which has tensile strain relative to the GaAs substrate, the product of the tensile strain and the thickness of each of the first and second barrier layers being 5 to 20% nm. The quantum-well active layer is 6 to 10 nm in thickness and is of a composition which has compressive strain of not smaller than 1.0% relative to the GaAs substrate. The sum of the product of the tensile strain and the thickness of the first barrier layer and that of the second barrier layer is larger than the product of the compressive strain and the thickness of the quantum-well active layer.

Semiconductor laser

A semiconductor laser device comprises a GaAs substrate, a first cladding layer having either one of p-type electrical conductivity and n-type electrical conductivity, a first optical waveguide layer, an In.sub.x2 Ga.sub.1-x2 As.sub.1-y2 P.sub.y2 first barrier layer, an In.sub.x3 Ga.sub.1-x3 As.sub.1-y3 P.sub.y3 quantum well active layer, an In.sub.x2 Ga.sub.1-x2 As.sub.1-y2 P.sub.y2 second barrier layer, a second optical waveguide layer, and a second cladding layer having the other electrical conductivity, the layers being overlaid in this order on the substrate. Each cladding layer and each optical waveguide layer have compositions, which are lattice matched with the substrate. Each of the first and second barrier layers has a tensile strain with respect to the substrate and is set such that a total layer thickness of the barrier layers may be 10 nm to 30 nm, and a product of a strain quantity of the tensile strain and the total layer thickness may be 0.05 nm to 0.2 nm. The active layer has a composition, which is lattice matched with the substrate, or a composition, which has a tensile strain of at most 0.003 with respect to the substrate.

Semiconductor laser device

A III-V group semiconductor laser includes a first clad layer, a first optical waveguide layer, a first barrier layer, an active layer, a second barrier layer, a second optical waveguide layer and a second clad layer formed in this order on a GaAs substrate which is a III-V group compound semiconductor. Each of the first and second clad layers and the first and second optical waveguide layers is of a composition which matches with the GaAs substrate in lattice. The active layer is of a composition which induces compressive strain on the GaAs substrate. Each of the first and second barrier layers is of a composition which induces tensile strain on the GaAs substrate, thereby compensating for the compressive strain induced in the active layer. The ratio of V group elements contained in the first optical waveguide layer is the same as that in the first barrier layer, and the ratio of V group elements contained in the second optical waveguide layer is the same as that in the second barrier layer.

A semiconductor laser includes a first clad layer, a first optical waveguide layer, a first barrier layer, an active layer, a second barrier layer, a second optical waveguide layer and a second clad layer formed in this order on a GaAs substrate which is a III-V group compound semiconductor. Each of the layers contains As and P, each of the first and second clad layers and the first and second optical waveguide layers is of a composition which matches with the GaAs substrate in lattice. The active layer is of a composition which induces compression strain on the GaAs substrate, and each of the first and second barrier layers is of a composition which induces tensile strain on the GaAs substrate, thereby compensating for the compression strain induced in the active layer.

Growing community of inventors

Kaisei-machi, Japan

Mitsugu Wada