Abstract: A photoelectric conversion element includes a buffer layer, a BSF layer, a base layer, a photoelectric conversion layer, an emitter layer, a window layer, a contact layer, and a p-type electrode sequentially on one surface of a substrate, and includes an n-type electrode on the other surface of the substrate. The photoelectric conversion layer has at least one quantum dot layer. The at least one quantum dot layer includes a quantum dot and a barrier layer. A photoelectric conversion member including the buffer layer, the BSF layer, the base layer, the photoelectric conversion layer, the emitter layer, the window layer, and the contact layer has an edge of incidence that receives light in an oblique direction relative to the growth direction of the quantum dot. A concentrator concentrates sunlight and causes the concentrated sunlight to enter the photoelectric conversion member from the edge of incidence.

Abstract: A semiconductor light-emitting element includes: a lower clad layer 12 that is provided on a substrate 10; an active layer 20 that is provided on the lower clad layer 12 and includes a quantum well layer 24 and a plurality of quantum dots 28 sandwiching a second barrier layer 22b together with the quantum well layer 24; and an upper clad layer 14 that is provided on the active layer 20, wherein a distance D between the quantum well layer 24 and the plurality of quantum dots 28 is smaller than an average of distances X between centers of the plurality of quantum dots 28.

Abstract: A photoelectric conversion element includes a buffer layer, a BSF layer, a base layer, a photoelectric conversion layer, an emitter layer, a window layer, a contact layer, and a p-type electrode sequentially on one surface of a substrate, and includes an n-type electrode on the other surface of the substrate. The photoelectric conversion layer has at least one quantum dot layer. The at least one quantum dot layer includes a quantum dot and a barrier layer. A photoelectric conversion member including the buffer layer, the BSF layer, the base layer, the photoelectric conversion layer, the emitter layer, the window layer, and the contact layer has an edge of incidence that receives light in an oblique direction relative to the growth direction of the quantum dot. A concentrator concentrates sunlight and causes the concentrated sunlight to enter the photoelectric conversion member from the edge of incidence.

Abstract: A semiconductor light-emitting element includes: a lower clad layer 12 that is provided on a substrate 10; an active layer 20 that is provided on the lower clad layer 12 and includes a quantum well layer 24 and a plurality of quantum dots 28 sandwiching a second barrier layer 22b together with the quantum well layer 24; and an upper clad layer 14 that is provided on the active layer 20, wherein a distance D between the quantum well layer 24 and the plurality of quantum dots 28 is smaller than an average of distances X between centers of the plurality of quantum dots 28.

Abstract: Included are: an active layer provided between an upper multilayer film reflecting mirror and a lower multilayer film reflecting mirror formed on a GaAs substrate and formed of a periodic structure of a low-refractive-index layer formed of AlxGa1-xAs (0.8?x?1) and a high-refractive-index layer formed of AlyGa1-yAs (0?y?x), at least one of the low-refractive-index layer and the high-refractive-index layer being of n-type; and a lower electrode provided between the lower multilayer film reflecting mirror and the active layer and configured to inject an electric current into the active layer.

Abstract: Included are: an active layer provided between an upper multilayer film reflecting mirror and a lower multilayer film reflecting mirror formed on a GaAs substrate and formed of a periodic structure of a low-refractive-index layer formed of AlxGa1-xAs (0.8?x?1) and a high-refractive-index layer formed of AlyGa1-yAs (0?y?x), at least one of the low-refractive-index layer and the high-refractive-index layer being of n-type; and a lower electrode provided between the lower multilayer film reflecting mirror and the active layer and configured to inject an electric current into the active layer.

Abstract: A surface emitting laser is formed of a composition in which bandgap energy of layers from immediately above a current confinement layer to a second conductivity type contact layer is reduced towards the second conductivity type contact layer in a stacking direction, and a composition in which bandgap energy of layers from immediately below the current confinement layer to a first conductivity type contact layer is reduced towards the first conductivity type contact layer in a stacking direction while bypassing a quantum well layer or a quantum dot of an active layer, and includes a second conductivity type cladding layer including a material for reducing the mobility of carriers.

Abstract: Included are: an active layer provided between an upper multilayer film reflecting mirror and a lower multilayer film reflecting mirror formed on a GaAs substrate and formed of a periodic structure of a low-refractive-index layer formed of AlxGa1-xAs (0.8?x?1) and a high-refractive-index layer formed of AlyGa1-yAs (0?y?x), at least one of the low-refractive-index layer and the high-refractive-index layer being of n-type; and a lower electrode provided between the lower multilayer film reflecting mirror and the active layer and configured to inject an electric current into the active layer.

Abstract: A surface emitting laser includes a cavity region formed on a group-III-V compound substrate, which includes an active layer and a current confinement layer that has an aluminum oxide compound and confines a current path through which a current is injected into the active layer, an upper DBR mirror and a lower DBR mirror formed on the substrate, sandwiching the cavity region, and a graded-composition layer disposed to contact the current confinement layer, which has an aluminum composition ratio decreasing monotonically as a distance from the current confinement layer increases. The graded-composition layer includes a first region that contacts the current confinement layer and an oxidation stop layer that contacts the first region and that has a change rate of the aluminum composition ratio larger than that of the first region. The graded-composition layer is oxidized from an interface with the current confinement layer to at least a portion of the oxidation stop layer.

Abstract: A method of performing a wafer level burn-in test for a plurality of surface-emitting laser devices formed on a wafer includes causing a plurality of contact electrodes arranged in a same plane with a pitch same as that of the surface-emitting laser devices being electrically connected to each other to have contact with pad electrodes of the surface-emitting laser devices, respectively, and applying a current to second electrodes of the surface-emitting laser devices and the contact electrodes. The wafer level burn-in test is performed while heating the wafer at a predetermined temperature. Laser lights emitted from the surface-emitting laser devices are monitored during the wafer level burn-in test.

Abstract: To provide a surface emitting laser device including a substrate; an optical resonator arranged on the substrate, the optical resonator including a lower multilayer reflector and an upper multilayer reflector; a strained active layer arranged in the resonator, the strained active layer having a multiple quantum well structure formed with a quantum well layer and a barrier layer; and a current confinement layer arranged on an upper side of the strained active layer, the current confinement layer including a selectively oxidized portion, where the current confinement layer is arranged at a position where a strain in the selectively oxidized portion influences the strained active layer.

Abstract: A surface emitting laser includes a cavity region formed on a group-III-V compound substrate, which includes an active layer and a current confinement layer that has an aluminum oxide compound and confines a current path through which a current is injected into the active layer, an upper DBR mirror and a lower DBR mirror formed on the substrate, sandwiching the cavity region, and a graded-composition layer disposed to contact the current confinement layer, which has an aluminum composition ratio decreasing monotonically as a distance from the current confinement layer increases. The graded-composition layer includes a first region that contacts the current confinement layer and an oxidation stop layer that contacts the first region and that has a change rate of the aluminum composition ratio larger than that of the first region. The graded-composition layer is oxidized from an interface with the current confinement layer to at least a portion of the oxidation stop layer.

Abstract: A surface emitting laser is formed of a composition in which bandgap energy of layers from immediately above a current confinement layer to a second conductivity type contact layer is reduced towards the second conductivity type contact layer in a stacking direction, and a composition in which bandgap energy of layers from immediately below the current confinement layer to a first conductivity type contact layer is reduced towards the first conductivity type contact layer in a stacking direction while bypassing a quantum well layer or a quantum dot of an active layer, and includes a second conductivity type cladding layer including a material for reducing the mobility of carriers.

Abstract: A surface emitting laser element that includes a cylindrical mesa post in which a plurality of semiconductor layers including an active layer is grown and that emits a laser light in a direction perpendicular to a substrate surface, the surface emitting laser element including a dielectric multilayer film on a top surface of the mesa post in at least a portion over a current injection area of the active layer; and a dielectric portion that includes layers fewer than layers of the dielectric multilayer film and that is arranged on a portion excluding the portion over the current injection area on the top surface of the mesa post and on at least part of a side surface of the mesa post.

Abstract: A surface emitting laser element array comprises a plurality of surface emitting laser elements (15) on a same substrate (1) each comprising a mesa post formed of a laminated structure including an active layer (4) for reducing a crosstalk between the surface emitting laser elements constituting the surface emitting laser element array, and for improving a high speed response, wherein each of the surface emitting laser elements (15) comprises a first electrode (9), a second electrode (10) and a third electrode (11) that have a polarity different from that of the first electrode (9); the first electrode (9) is arranged on the mesa post; the second electrode (10) is arranged on one surface of the substrate (1) same as that of the first electrode (9); the third electrode (11) is arranged on the other surface of the substrate (1) opposite to that of the first electrode and the second electrode (9, 10) and is provided as a common electrode of the surface emitting laser elements (15); and an electric current is app

Abstract: A selective oxidation layer is formed by alternately growing an AlAs layer and an XAs layer containing a group III element X with a thickness ratio in a range between 97:3 and 99:1 on a plurality of semiconductor layers including an active layer. The selective oxidation layer is selectively oxidized to manufacture a vertical-cavity surface-emitting laser.

Abstract: A vertical-cavity surface-emitting (VCSEL) device has a layer structure including a top DBR mirror, an active layer, a current confinement oxide layer, and a bottom DBR mirror, the layer structure being configured as a mesa post. The current confinement oxide layer has a central current injection area and a peripheral current blocking area oxidized from the sidewall of the mesa post. The mesa post has a substantially square cross-sectional shape, thereby allowing an oxidation heat treatment to configure a substantially circular current injection area in the current-confinement oxide layer.

Abstract: Provided is a surface emitting laser element array of low cost and high reliability. The surface emitting laser element array has a substrate having a semiconductor of a first conduction type; and a plurality of surface emitting laser elements each having, above the substrate, an active layer sandwiched between a first conduction type semiconductor layer area and a second conduction type semiconductor layer area and disposed between a upper reflective mirror and a lower reflective mirror, the surface emitting laser elements being separated from each other by an electric separation structure formed having such a depth as to reach the substrate. The first conduction type semiconductor layer area is arranged between the substrate and the active layer.

Abstract: A method of performing a wafer level burn-in test for a plurality of surface-emitting laser devices formed on a wafer includes causing a plurality of contact electrodes arranged in a same plane with a pitch same as that of the surface-emitting laser devices being electrically connected to each other to have contact with pad electrodes of the surface-emitting laser devices, respectively, and applying a current to second electrodes of the surface-emitting laser devices and the contact electrodes. The wafer level burn-in test is performed while heating the wafer at a predetermined temperature. Laser lights emitted from the surface-emitting laser devices are monitored during the wafer level burn-in test.

Abstract: Included are: an active layer provided between an upper multilayer film reflecting mirror and a lower multilayer film reflecting mirror formed on a GaAs substrate and formed of a periodic structure of a low-refractive-index layer formed of AlxGa1-xAs (0.8?x?1) and a high-refractive-index layer formed of AlyGa1-yAs (0?y?x), at least one of the low-refractive-index layer and the high-refractive-index layer being of n-type; and a lower electrode provided between the lower multilayer film reflecting mirror and the active layer and configured to inject an electric current into the active layer.