Abstract: A semiconductor optical element includes: a first conductivity type semiconductor substrate; and a laminated body disposed on the first conductivity type semiconductor substrate. The laminated body includes, in the following order from a side of the first conductivity type semiconductor substrate: a first conductivity type semiconductor layer; an active layer; a second conductivity type semiconductor layer; and a second conductivity type contact layer. The second conductivity type semiconductor layer includes: a carbon-doped semiconductor layer in which carbon is doped as a dopant in a compound semiconductor; and a group 2 element-doped semiconductor layer in which a group 2 element is doped as a dopant in a compound semiconductor. The carbon-doped semiconductor layer is disposed at a position closer to the active layer than the group 2 element-doped semiconductor layer.

Abstract: A semiconductor optical element includes: a first conductivity type semiconductor substrate; and a laminated body disposed on the first conductivity type semiconductor substrate. The laminated body includes, in the following order from a side of the first conductivity type semiconductor substrate: a first conductivity type semiconductor layer; an active layer; a second conductivity type semiconductor layer; and a second conductivity type contact layer. The second conductivity type semiconductor layer includes: a carbon-doped semiconductor layer in which carbon is doped as a dopant in a compound semiconductor; and a group 2 element-doped semiconductor layer in which a group 2 element is doped as a dopant in a compound semiconductor. The carbon-doped semiconductor layer is disposed at a position closer to the active layer than the group 2 element-doped semiconductor layer.

Abstract: A semiconductor optical element includes: a first conductivity type semiconductor substrate; and a laminated body disposed on the first conductivity type semiconductor substrate. The laminated body includes, in the following order from a side of the first conductivity type semiconductor substrate: a first conductivity type semiconductor layer; an active layer; a second conductivity type semiconductor layer; and a second conductivity type contact layer. The second conductivity type semiconductor layer includes: a carbon-doped semiconductor layer in which carbon is doped as a dopant in a compound semiconductor; and a group 2 element-doped semiconductor layer in which a group 2 element is doped as a dopant in a compound semiconductor. The carbon-doped semiconductor layer is disposed at a position closer to the active layer than the group 2 element-doped semiconductor layer.

Abstract: A semiconductor optical element includes: a first conductivity type semiconductor substrate; and a laminated body disposed on the first conductivity type semiconductor substrate. The laminated body includes, in the following order from a side of the first conductivity type semiconductor substrate: a first conductivity type semiconductor layer; an active layer; a second conductivity type semiconductor layer; and a second conductivity type contact layer. The second conductivity type semiconductor layer includes: a carbon-doped semiconductor layer in which carbon is doped as a dopant in a compound semiconductor; and a group 2 element-doped semiconductor layer in which a group 2 element is doped as a dopant in a compound semiconductor. The carbon-doped semiconductor layer is disposed at a position closer to the active layer than the group 2 element-doped semiconductor layer.

Abstract: In a method for manufacturing a semiconductor laser having a p-InP current blocking layer and an n-InP current blocking layer formed on both sides of an active layer, the length of surface migration is controlled to be not less than 1500 nm when forming the n-InP current blocking layer. This makes it possible to effectively prevent abnormal growth of the n-InP current blocking layer from taking place.

Abstract: First, a waveguide which lases in accordance with a predetermined voltage applied thereto is formed on a predetermined region on a substrate. An SiO2 mask is formed on a top of the waveguide. Then, a current-blocking layer of group III material and group V material for blocking a current is formed on the substrate and the waveguide except a top of the waveguide on which the SiO2 mask is formed. In this step, the group III material including group III elements and the group V material including group V elements in the current-blocking layer are supplied to the surface of the substrate. A migration length of the group III material on the surface is controlled by controlling at least one of the growth temperature of the current-blocking layer and the pressure of the supplied group V material. And a cladding layer is formed after the SiO2 mask is removed, on the waveguide and the current-blocking layer and a contact layer is formed on the cladding layer.

Abstract: A method for making an optical semiconductor element including the steps of: forming two growth-blocking mask stripes of silicon dioxide film on a first conductivity type compound semiconductor substrate; selectively forming a double-heterostructure which comprises a first conductivity type cladding layer, a light absorption layer and a second conductivity type cladding layer on a mask opening region by the metal organic vapor phase epitaxy method; partially removing the mask stripes on both sides of the double-heterostructure and opposite sides of the mask stripes thereof to provide further opening regions; and selectively forming a burying structure on the double-heterostructure by the metal organic vapor phase epitaxy method.

Abstract: The invention realizes an optical modulator which prevents occurrence of an edge breakdown and is improved in extinction characteristic and voltage resisting property. The optical modulator comprises an oxide film formed as a growth inhibiting film on a compound semiconductor substrate of a first conduction type, a double heterostructure including a clad layer of the first conduction type, a light absorbing layer and a clad layer of a second conduction type successively formed in an opening of the oxide film, and an embedding structure for covering over the entire double heterostructure. The optical modulator is characterized in that the carrier concentration of the clad layer of the first conduction type exhibits a continuous variation from the semiconductor substrate to the light absorbing layer or the carrier concentration of the embedding structure portion exhibits a variation from a low concentration to a high concentration.