Abstract: An optical semiconductor element includes, in order, a semiconductor laser, an optical waveguide, a loop waveguide, and a ring resonator optically coupled to the loop waveguide, in which a distance between the semiconductor laser and the ring resonator is 1 ?m or more and 200 ?m or less.

Abstract: A semiconductor photonic device includes a first cladding layer formed on a substrate formed with Si, a semiconductor layer formed on the first cladding layer, and a second cladding layer formed on the semiconductor layer. In the semiconductor layer, an active layer, and a p-type layer and an n-type layer disposed in contact with the active layer while sandwiching the active layer in a planar view are formed. A p-type electrode is electrically connected to the p-type layer, and an n-type electrode is electrically connected to the n-type layer. The active layer is formed in a core shape extending in a predetermined direction. This semiconductor photonic device also includes an optical coupling layer that is buried in the first cladding layer in such a manner as to be optically coupled to the active layer, and is formed in a core shape extending along the active layer.

Abstract: An embodiment photodetector includes a clad layer formed on a substrate, a first semiconductor layer formed on the clad layer, and a second semiconductor layer and a third semiconductor layer with the first semiconductor layer interposed therebetween formed on the clad layer. The photodetector includes a light absorbing layer made of an n-type III-V compound semiconductor formed on the first semiconductor layer through an insulating layer.

Abstract: An embodiment semiconductor optical device includes an optical waveguide including a core, and an active layer extending in the waveguide direction of the optical waveguide for a predetermined distance and arranged in a state in which the active layer can be optically coupled to the core. The core and the active layer are arranged in contact with each other. The core is formed of a material with a refractive index of about 1.5 to 2.2, such as SiN, for example. In addition, the core is formed to a thickness at which a higher-order mode appears. The higher-order mode is an E12 mode, for example.

Abstract: A light receiving device includes, on a substrate, a Si waveguide core provided in a dielectric layer, a first i-type waveguide clad, an i-type core layer, a second i-type waveguide clad, p-type layers disposed on one side of a side surface of a layered structure in a light waveguide direction, the layered structure including the first i-type waveguide clad, the i-type core layer, and the second i-type waveguide clad, n-type layers disposed on the other side, and an electrode on a surface of each of the n-type layers. A width of the Si waveguide core is set to be able to suppress absorption of light in a vicinity of an input edge of the i-type core layer.

Abstract: An optical phase modulator includes a lower cladding layer, a core formed on the lower cladding layer, an upper cladding layer formed over the core, and a heater. In addition, the optical phase modulator includes a semiconductor layer which is embedded in the upper cladding layer, is disposed above the core, and is formed of a compound semiconductor, and the heater is constituted by an impurity introduction region formed in the semiconductor layer.

Abstract: A light reception device of the present invention includes a first i-type cladding region, an n-type waveguide core having a predetermined width, and a second i-type cladding region in contact with a side surface of the n-type waveguide core on a substrate, includes a p-type absorption layer, a p-type diffusion barrier layer, a p-type contact layer, and a p-type electrode formed in an upper part above a region including a part of the n-type waveguide core, with an i-type insertion layer interposed between the upper part and the region, and includes an n-type electrode on an upper surface of another part of the n-type waveguide core.

Abstract: A semiconductor optical device includes a light emitting layer that emits light in a state of current injection; an optical waveguide in which a width or a thickness in an extending direction (y) of the light emitting layer varies along the extending direction; and a uniform diffraction grating having constant cycle, width and depth, wherein the light emitting layer, the optical waveguide and the uniform diffraction grating are arranged at positions where the light emitting layer, the optical waveguide, and the uniform diffraction grating are optically coupled to one another, the uniform diffraction grating is arranged above the light emitting layer, the optical waveguide is arranged below the light emitting layer, and the optical waveguide includes, in the extending direction, a first portion having a predetermined width, a second portion having a larger width than the width of the first portion, and a third portion having the same width as the width of the first portion.

Abstract: A core, constituted by an amorphous undoped semiconductor (i type), which is formed on a lower clad layer, and a p-type layer and an n-type layer which are disposed on the lower clad layer with the core interposed therebetween and are formed in contact with the core are provided. The core is formed to be thicker than the p-type layer and the n-type layer. The p-type layer and the n-type layer are constituted by single crystal silicon.

Abstract: A silicon nitride core is formed on a silicon core via a first silicon oxide layer, and a germanium pattern caused to selectively grow in an opening penetrating through a second silicon oxide layer formed on the silicon nitride core and the first silicon oxide layer is formed on a lower silicon pattern formed to be continuous with the silicon core, thereby constituting a Ge photodiode.

Abstract: Provided is a photodetector which can be manufactured in a standard process of a mass-produced CMOS foundry. The photodetector includes a silicon (Si) substrate; a lower clad layer; a core layer including a waveguide layer configured to guide signal light, and including a first Si slab doped with first conductive impurity ions and a second Si slab doped with second conductive impurity ions; a germanium (Ge) layer configured to absorb light and including a Ge region doped with the first conductive impurity ions; an upper clad layer; and electrodes respectively connected to the first and second Si slabs and the Ge region. A region of the core layer sandwiched between the first Si slab and the second Si slab operates as an amplification layer.

Abstract: A semiconductor layer formed on a clad layer and a light absorbing layer formed on the semiconductor layer are provided. The semiconductor layer includes a p-type region and an n-type region. The p-type region, which is of p-type, is provided on a side of one side portion of the light absorbing layer in a direction perpendicular to a direction in which light is guided, and the n-type region, which is of n-type, is provided on a side of another side portion of the light absorbing layer in the direction perpendicular to the direction in which light is guided. A p-type contact layer, which is of p-type, is formed on the p-type region, and an n-type contact layer is formed on the n-type region.

Abstract: Provided is a tunable laser that prevents basic characteristics of the laser from deteriorating and enables a high-speed control of the oscillation wavelength. The tunable laser includes a semiconductor gain portion including a III-V compound semiconductor, an optical feedback portion configured to diffract light generated in the semiconductor gain portion and feed the diffracted light back to the semiconductor gain portion, and an optical modulation portion including an optical waveguide that contains doped indirect transition-type silicon. The semiconductor gain portion and the optical modulation portion are disposed so that optical modes thereof overlap each other, and the semiconductor gain portion includes an embedded active layer thin film of a type in which a current is injected in a lateral direction.

Abstract: An embodiment semiconductor optical device includes an optical waveguide including a core, and an active layer extending in the waveguide direction of the optical waveguide for a predetermined distance and arranged in a state in which the active layer can be optically coupled to the core. The core and the active layer are arranged in contact with each other. The core is formed of a material with a refractive index of about 1.5 to 2.2, such as SiN, for example. In addition, the core is formed to a thickness at which a higher-order mode appears. The higher-order mode is an E12 mode, for example.

Abstract: A semiconductor layer formed on a clad layer and a light absorbing layer formed on the semiconductor layer are provided. The semiconductor layer includes a p-type region and an n-type region. The p-type region, which is of p-type, is provided on a side of one side portion of the light absorbing layer in a direction perpendicular to a direction in which light is guided, and the n-type region, which is of n-type, is provided on a side of another side portion of the light absorbing layer in the direction perpendicular to the direction in which light is guided. A p-type contact layer, which is of p-type, is formed on the p-type region, and an n-type contact layer is formed on the n-type region.