Hamamatsu-photonics K.k.

Masahiro Hitaka

Tadataka Edamura

Akio Ito

Tatsuo Dougakiuchi

Kazuue Fujita

Yoshitaka Kurosaka

Kazuyoshi Hirose

Takahiro Sugiyama

Atsushi Sugiyama

Akira Higuchi

Kousuke Shibata

Yutaka Takagi

A QCL includes a semiconductor substrate and an active layer provided on the semiconductor substrate. The active layer has a cascade structure in which a unit laminate including a light emission layer which generates light and an injection layer to which electrons are transported from the light emission layer is laminated in multiple stages. The light emission layer and the injection layer each have a quantum well structure in which quantum well layers and barrier layers are alternately laminated. A separation layer including a separation quantum well layer having a layer thickness smaller than an average layer thickness of the quantum well layers included in the light emission layer and smaller than an average layer thickness of the quantum well layers included in the injection layer is provided between the light emission layer and the injection layer in the unit laminate.

Quantum cascade laser

The light-emitting element of an embodiment outputs a clear optical image while suppressing light output efficiency reduction, and includes a substrate, a light-emitting unit, and a bonding layer. The light-emitting unit has a semiconductor stack, including a phase modulation layer, between first and second electrodes. The phase modulation layer has a base layer and modified refractive index regions, and includes a first region having a size including the second electrode, and a second region. Each gravity center of the second region's modified refractive index region is arranged by an array condition. The light from the stack is a single beam, and regarding a first distance from the substrate to the stack's front surface and a second distance from the substrate to the stack's back surface, a variation amount of the first distance along a direction on the substrate is smaller than a variation amount of the second distance.

Light emitting element, method for manufacturing light emitting element, and method for designing phase modulation layer

A quantum cascade laser device includes a semiconductor substrate, an active layer provided on the semiconductor substrate, and an upper clad layer provided on a side of the active layer opposite to the semiconductor substrate side and having a doping concentration of impurities of less than 1×10cm. Unit laminates included in the active layer each include a first emission upper level, a second emission upper level, and at least one emission lower level in their subband level structure. The active layer is configured to generate light having a center wavelength of 10 μm or more due to electron transition between at least two levels of the first emission upper level, the second emission upper level, and the at least one emission lower level in the light emission layer in each of the unit laminates.

Quantum cascade laser device

Fluid analyzer

An optical semiconductor element includes a semiconductor substrate, a first laminated structure provided on a front surface of the semiconductor substrate, and a second laminated structure provided on the front surface of the semiconductor substrate, the first laminated structure includes a first quantum cascade region, the second laminated structure includes a dummy region having the same layer structure as the first quantum cascade region, a second quantum cascade region provided on the front surface of the semiconductor substrate via the dummy region, and one of the first quantum cascade region and the second quantum cascade region is a quantum cascade laser, and the other of the first quantum cascade region and the second quantum cascade region is a quantum cascade detector.

Optical semiconductor element and method of manufacturing optical semiconductor element

A semiconductor laser device of an embodiment comprises: a first electrode having an opening for passage of laser light and arranged on a main surface of a substrate; and a second electrode arranged on a back surface of the substrate. A stacked structural body including an active layer and a photonic crystal layer is arranged between the substrate and the first electrode, and a current confinement layer having an opening for passage of a current is arranged between the stacked structural body and the first electrode. A maximum width of the opening of the current confinement layer is smaller than a maximum width of the opening of the first electrode, and a whole region defined by the opening of the current confinement layer fits within a region defined by the opening of the first electrode as viewed from the first electrode side toward the second electrode side.

Semiconductor laser device

A DFB laser element includes an active layerhaving a multiple quantum well structure including a plurality of well layersB having different thicknesses, a diffraction grating layerthat is optically coupled to the active layer, and a pair of cladding layers with the active layerand the diffraction grating layerinterposed therebetween. An effective refractive index of the diffraction grating layeris high, and a thickness of the well layerB increases as a distance from the diffraction grating layerincreases. In this structure, it is possible to reduce dependence on temperature when the DFB semiconductor laser element is miniaturized.

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Hamamatsu, Japan

Masahiro Hitaka