Abstract: In a constitution where a first clad layer is formed on a semiconductor substrate, an active layer having the strained multiple quantum well structure is formed on the first clad layer, and a second clad layer is formed on the active layer, the sum of products of strain amounts and film thickness in the active layer is set to a negative value.

Abstract: A semiconductor laser device in which a red semiconductor laser device and an infrared semiconductor laser device are located on a single substrate, and an end-face window structure is formed simultaneously. The hydrogen concentration (1.5e18 cm?3) of a fourth clad layer (110) of the infrared semiconductor laser device is higher than the hydrogen concentration (1e18 cm?3) of a second clad layer (105) of the red semiconductor laser device which is a first semiconductor laser device, whereby an active layer of the infrared semiconductor laser device can be sufficiently disordered in the semiconductor laser device.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: A semiconductor laser device includes: a first light emitting device, the first light emitting device including a first first-conductive-type cladding layer, a first active layer having a first window region in the vicinity of a light emitting edge surface and a first second-conductive-type cladding layer stacked in this order on a substrate; and a second light emitting device, the second light emitting device including a second first-conductive-type cladding layer, a second active layer having a second window region in the vicinity of a light emitting edge surface and a second second-conductive-type cladding layer stacked in this order on the substrate. In the semiconductor laser device, respective lattice constants of the first second-conductive-type and second second-conductive-type cladding layers are adjusted to compensate for a difference in diffusion rate of an impurity between the first window region in the first active layer and the second window region in the second active layer.

Abstract: A semiconductor substrate comprises a semiconductor layer comprising a group III nitride as a main component. A scattering portion for scattering an incident beam of light incident on one plane of the semiconductor layer is provided on another plane or inside of the semiconductor layer.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: A semiconductor substrate comprises a semiconductor layer comprising a group III nitride as a main component. A scattering portion for scattering an incident beam of light incident on one plane of the semiconductor layer is provided on another plane or inside of the semiconductor layer.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: In a constitution where a first clad layer is formed on a semiconductor substrate, an active layer having the strained multiple quantum well structure is formed on the first clad layer, and a second clad layer is formed on the active layer, the sum of products of strain amounts and film thickness in the active layer is set to a negative value

Abstract: A semiconductor laser device in which a red semiconductor laser device and an infrared semiconductor laser device are located on a single substrate, and an end-face window structure is formed simultaneously. The hydrogen concentration (1.5e18 cm?3) of a fourth clad layer (110) of the infrared semiconductor laser device is higher than the hydrogen concentration (1e18 cm?3) of a second clad layer (105) of the red semiconductor laser device which is a first semiconductor laser device, whereby an active layer of the infrared semiconductor laser device can be sufficiently disordered in the semiconductor laser device.

Abstract: A semiconductor laser device includes: a first light emitting device, the first light emitting device including a first first-conductive-type cladding layer, a first active layer having a first window region in the vicinity of a light emitting edge surface and a first second-conductive-type cladding layer stacked in this order on a substrate; and a second light emitting device, the second light emitting device including a second first-conductive-type cladding layer, a second active layer having a second window region in the vicinity of a light emitting edge surface and a second second-conductive-type cladding layer stacked in this order on the substrate. In the semiconductor laser device, respective lattice constants of the first second-conductive-type and second second-conductive-type cladding layers are adjusted to compensate for a difference in diffusion rate of an impurity between the first window region in the first active layer and the second window region in the second active layer.

Abstract: The semiconductor laser according to the present invention has a substrate used as a shared base, on which an infrared laser diode portion and a red laser diode portion are formed apart from each other. The top surfaces of the laminated layers of the individual laser diode portions have different height positions in the thickness direction of the substrate in relation to the reference point Bf. Neighboring members are formed on the outer edge of the laser, sandwiching therebetween where the laser diode portions are formed. The top surface positions of the neighboring members are all set to the same height which is higher than or equal to the top surface position of the higher laser diode portion of the two.

Abstract: A semiconductor substrate comprises a semiconductor layer comprising a group III nitride as a main component. A scattering portion for scattering an incident beam of light incident on one plane of the semiconductor layer is provided on another plane or inside of the semiconductor layer.

Abstract: A semiconductor substrate comprises a semiconductor layer comprising a group III nitride as a main component. A scattering portion for scattering an incident beam of light incident on one plane of the semiconductor layer is provided on another plane or inside of the semiconductor layer.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: A semiconductor substrate comprises a semiconductor layer comprising a group III nitride as a main component. A scattering portion for scattering an incident beam of light incident on one plane of the semiconductor layer is provided on another plane or inside of the semiconductor layer.

Abstract: A semiconductor substrate comprises a semiconductor layer comprising a group III nitride as a main component. A scattering portion for scattering an incident beam of light incident on one plane of the semiconductor layer is provided on another plane or inside of the semiconductor layer.

Abstract: An n-type GaAs buffer layer 702, an n-type AlGaInP cladding layer 703, a multiple quantum well active layer 704 made of AlGaInP and GaInP, a first p-type AlGaInP cladding layer 705a, an optical guide layer 707, a second p-type cladding layer 705b, a p-type GaInP saturable absorption layer 706, and a third p-type AlGaInP cladding layer 707 are sequentially formed on an n-type GaAs substrate 701. In this structure, the volume of the saturable absorption layer is reduced, and the optical guide layer is provided. As the volume of the saturable absorption layer becomes smaller, the more easily the carrier density can be increased, the more easily the saturated state can be attained, and the more remarkable the saturable absorption effect becomes. Thus, a semiconductor laser having stable self-oscillation characteristics and, as a result, having a low relative noise intensity is realized.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.