Abstract: A semiconductor optical element includes a semiconductor layer portion that includes an optical waveguide layer. The semiconductor layer portion contains a first impurity having a function of suppressing atomic vacancy diffusion and a second impurity having a function of promoting atomic vacancy diffusion, between a topmost surface of the semiconductor layer portion and the optical waveguide layer. The semiconductor layer portion includes two or more regions that extend in a deposition direction. At least one of the two or more regions contains both the first impurity and the second impurity. The two or more regions have different degrees of disordering in the optical waveguide layer achieved through atomic vacancy diffusion and different band gap energies of the optical waveguide layer.

Abstract: A semiconductor laser element includes: a window region including a disordered portion formed by diffusion of a group-III vacancy, the diffusion promoted by providing on the window region a promoting film that absorbs a predetermined atom; a non-window region including an active layer of a quantum well structure; and a difference equal to or larger than 50 meV between an energy band gap in the window region and an energy band gap in the non-window region.

Abstract: A semiconductor laser element includes: a window region including a disordered portion formed by diffusion of a group-III vacancy, the diffusion promoted by providing on the window region a promoting film that absorbs a predetermined atom; a non-window region including an active layer of a quantum well structure; and a difference equal to or larger than 50 meV between an energy band gap in the window region and an energy band gap in the non-window region.

Abstract: A semiconductor optical element includes a semiconductor layer portion that includes an optical waveguide layer. The semiconductor layer portion contains a first impurity having a function of suppressing atomic vacancy diffusion and a second impurity having a function of promoting atomic vacancy diffusion, between a topmost surface of the semiconductor layer portion and the optical waveguide layer. The semiconductor layer portion includes two or more regions that extend in a deposition direction. At least one of the two or more regions contains both the first impurity and the second impurity. The two or more regions have different degrees of disordering in the optical waveguide layer achieved through atomic vacancy diffusion and different band gap energies of the optical waveguide layer.

Abstract: A semiconductor laser element includes: a window region including a disordered portion formed by diffusion of a group-III vacancy, the diffusion promoted by providing on the window region a promoting film that absorbs a predetermined atom; a non-window region including an active layer of a quantum well structure; and a difference equal to or larger than 50 meV between an energy band gap in the window region and an energy band gap in the non-window region.

Abstract: A method of manufacturing a semiconductor device including a semiconductor layer and a dielectric layer deposited on the semiconductor layer, including: forming the semiconductor layer; performing a surface treatment for removing a residual carbon compound, on a surface of the semiconductor layer formed; forming a dielectric film under a depositing condition corresponding to a surface state after the surface treatment, on at least a part of the surface of the semiconductor layer on which the surface treatment has been performed; and changing a crystalline state of at least a partial region of the semiconductor layer by performing a heat treatment on the semiconductor layer on which the dielectric film has been formed.

Abstract: A method of manufacturing a semiconductor device including a semiconductor layer and a dielectric layer deposited on the semiconductor layer, including: forming the semiconductor layer; performing a surface treatment for removing a residual carbon compound, on a surface of the semiconductor layer formed; forming a dielectric film under a depositing condition corresponding to a surface state after the surface treatment, on at least a part of the surface of the semiconductor layer on which the surface treatment has been performed; and changing a crystalline state of at least a partial region of the semiconductor layer by performing a heat treatment on the semiconductor layer on which the dielectric film has been formed.

Abstract: A semiconductor laser element includes: a window region including a disordered portion formed by diffusion of a group-III vacancy, the diffusion promoted by providing on the window region a promoting film that absorbs a predetermined atom; a non-window region including an active layer of a quantum well structure; and a difference equal to or larger than 50 meV between an energy band gap in the window region and an energy band gap in the non-window region.

Abstract: A GaAs based semiconductor laser having a combination of cladding layers including a ridge structure part, and a remaining part which overlays the active layers of the laser, and an etch stop layer sandwiched between the ridge structure part and the remaining part. The remaining part preferably overlies the entire surface of laser active layers and has a thickness “D” which satisfies 1.1×W>D?0.5×W wherein W is the width of a spot size having a strength of 1/e2 as measured at the laser front facet in a direction perpendicular to the active layers, wherein “e” is the base of the natural logarithm. The semiconductor laser solves the kink phenomenon to obtain an excellent linear relationship between the optical output power and the injected current.

Abstract: A GaAs based semiconductor laser having a combination of cladding layers including a ridge structure part, and a remaining part which overlays the active layers of the laser, and an etch stop layer sandwiched between the ridge structure part and the remaining part. The remaining part preferably overlies the entire surface of laser active layers and has a thickness “D” which satisfies 1.1×W>D≧0.5×W wherein W is the width of a spot size having a strength of 1/e2 as measured at the laser front facet in a direction perpendicular to the active layers, wherein “e” is the base of the natural logarithm. The semiconductor laser solves the kink phenomenon to obtain an excellent linear relationship between the optical output power and the injected current.

Abstract: Provided is a ridge waveguide type semiconductor laser device in which fundamental transverse mode operation is stabilized and unstable jumps of a longitudinal mode (oscillation wavelength) never occur even with use of high optical output of 300 mW or more. The semiconductor laser device has a stacked structure composed of a substrate and layers thereon. The layers include a lower cladding layer, lower optical confinement layer, active layer, upper optical confinement layer, and upper cladding layer, which are built up in the order named. A ridge is formed on the upper cladding layer. The width (W) of the bottom ridge portion of the ridge ranges from 2.5 &mgr;m to 5.0 &mgr;m, and the distance from the bottom ridge portion to an active layer is adjusted to a value higher than 0.5 &mgr;m and not higher than 0.8 &mgr;m.

Abstract: A GaAs based semiconductor laser has a combination of cladding layers including a ridge structure part, and a remaining part which overlays the active layers of the laser, and an etch stop layer sandwiched between the ridge structure part and the remaining part. The remaining part preferably overlies the entire surface of laser active layers and has a thickness “D” which satisfies 1.1×W>D≧0.5×W wherein W is the width of a spot size having a strength of {fraction (1/e2)} as measured at the laser front facet in a direction perpendicular to the active layers, wherein “e” is the base of the natural logarithm. The semiconductor laser solves the kink phenomenon to obtain an excellent linear relationship between the optical output power and the injected current.

Abstract: A GaAs based semiconductor laser has a combination of cladding layers including a ridge structure part and a remaining part sandwiching therebetween an etch stop layer. The remaining part overlies the entire surface of laser active layers and has a thickness “D” which satisfies D≧W×0.5 wherein W is the width of a spot size having a strength of 1/e2 for a near field pattern in the active layer in a direction perpendicular to the active layer, wherein “e” is the bottom of the natural logarithm.

Abstract: A GaAs based semiconductor laser has a combination of cladding layers including a ridge structure part, and a remaining part which overlays the active layers of the laser, and an etch stop layer sandwiched between the ridge structure part and the remaining part. The remaining part preferably overlies the entire surface of laser active layers and has a thickness “D” which satisfies 1.1×W>D≧0.5×W wherein W is the width of a spot size having a strength of {fraction (1/e2)} as measured at the laser front facet in a direction perpendicular to the active layers, wherein “e” is the base of the natural logarithm. The semiconductor laser solves the kink phenomenon to obtain an excellent linear relationship between the optical output power and the injected current.

Abstract: In a quantum-well type semiconductor laser device comprising a multi-layered quantum-well layer (active layer) constituted by quantum-well layers and a corresponding number of barrier layers and a pair of optical confinement layers respectively arranged on and under the active layer, since the number of quantum-well layers is limited to one or two, the device has a reduced internal loss, a narrowed far-field angle and a bandgap energy of the quantum-well layers greater than that of the optical confinement layers by more than 160 meV so that it shows a lowered threshold current density. Besides, by selecting a thickness of the quantum-well layers between 3 and 8 nm, the device can be made to oscillate at the first quantum level in order to make the oscillation wavelength highly dependent on temperature and optical output and accordingly produce a high spectral purity.