Abstract: A method of manufacturing directional coupler includes forming a first waveguide over a substrate, forming a separate section on respective ends of the first waveguide, and forming a second waveguide stacked over the first waveguide, wherein the first waveguide and the second waveguide are patterned by ink-jet process. The first waveguide and the second waveguide may be formed so as to overlap each other. The method may further include forming a projecting portion on the substrate, wherein the first waveguide being formed on the projection portion.

Abstract: An optical element includes a surface-emitting type semiconductor laser, and a light-receiving element that detects a part of laser light emitted from the surface-emitting type semiconductor laser, wherein the light-receiving element is formed above the surface-emitting type semiconductor laser and includes a semiconductor layer having one or more layers, and at least one of the layers in the semiconductor layer has a plane configuration that has anisotropy.

Abstract: An optical element includes a substrate, a surface-emitting type semiconductor laser that is provided above the substrate and includes a first mirror, an active layer and a second mirror formed in this order from the substrate side, a first optical detection section formed above the substrate, a second optical detection section that is formed above the substrate and has a second photoabsorption layer, and an isolation layer formed between the surface-emitting type semiconductor laser and at least one of the first optical detection section and the second optical detection section. The first optical detection section includes a first photoabsorption layer formed above the substrate and a photonic crystal section formed above or below the first photoabsorption layer.

Abstract: The invention provides an optical multiplexing and demultiplexing device using a two-dimensional photonic crystal, in which miniaturization and higher integration thereof can be achieved; an optical communication apparatus; and an optical communication system. The optical multiplexing and demultiplexing device of the present invention includes a substrate; and a plurality of slab layers provided on the substrate. The slab layers each have a two-dimensional photonic crystal structure, in which low refractive index regions are periodically arranged. In addition, the slab layers have line defects, provided in part of the periodical arrangement so as to function as a waveguide, and at least point defects formed in the respective periodic arrangements, the point defects capturing light having a specific wavelength and introducing it to the line defects or capturing light having a specific wavelength from the line defects and radiating it.

Abstract: A method is provided to provide a photodetector that can enhance the light receiving sensitivity with a relatively simple structure, and that can maintain a high speed responsiveness. A photodetector having a MSM (Metal-Semiconductor-Metal) structure, including a substrate, a multilayer film that is disposed over the substrate and includes a low refractive index layer and a high refractive index layer that are alternately laminated as a unit cycle. At least one of the low refractive index layer and the high refractive index layer is a photoabsorption layer composed of semiconductor, and a portion that is embedded in the multilayer film, the portion having at least one pair of opposing electrodes within the multilayer film.

Abstract: The invention provides an optical switch using a two-dimensional photonic crystal capable of enabling higher integration, an optical communications device and an optical communications system. An optical switch of the present invention can include a substrate, a first slab layer and a second slab layer disposed over the substrate, a third slab layer provided over the substrate and placed between the first slab layer and the second slab layer, and a phase control area provided for the first slab layer and capable of controlling the phase of light passing through the slab layer. The slab layers can include a two-dimensional photonic crystal structure, a linear defect which functions as a waveguide, a point defect for emitting light and a point defect for trapping light. The point defect for trapping light in each of the first slab layer and the second slab layer and the point defect for emitting light in the third slab layer are positioned so as to face each other.

Abstract: An organic semiconductor device of the present invention has an organic semiconductor layer disposed within a depression formed in a substrate; a drain electrode and a source electrode; and a gate electrode to face the organic semiconductor layer with a gate insulating layer interposed. Alternatively, an organic semiconductor device of the present invention has an insulating layer disposed on a substrate; an organic semiconductor layer disposed within a depression formed in the insulating layer; a drain electrode and a source electrode; and a gate electrode disposed to face the organic semiconductor layer with a gate insulating layer interposed.

Abstract: A method is provided to precisely mount an optical device and an optical fiber without manual alignment. A tapered through-hole is provided in a substrate to house the optical device whose optical transmission point substantially coincides with a geometrical center. The optical transmitter having a larger diameter than a diameter of the optical device is further inserted in the tapered through-hole housing the optical device.

Abstract: A light-emitting device includes a substrate and a light-emitting device section. The light-emitting device section includes a light-emitting layer capable of emitting light by electroluminescence, a pair of electrode layers for applying an electric field to the light-emitting layer, an optical section for propagating light generated in the light-emitting layer in a specific direction, and an insulation layer disposed between the pair of electrode layers, having an opening formed in part thereof and can function as a current concentrating layer for specifying a region through which current to be supplied to the light-emitting layer flows via a layer in the opening. The optical section has a defect section which forms photonic bandgaps capable of inhibiting a three-dimensional spontaneous emission, and the energy level of the defect section, caused by the defect, is set to be within a specific emission spectrum.

Abstract: A light emitting device has a substrate and a light-emitting section formed on the substrate. The light-emitting section includes a light-emitting layer in which light is generated by electro-luminescence, first and second electrodes used to apply electric charges to the light-emitting layer, and first and second dielectric multi-layered films between which the light-emitting layer is interposed. The first and second electrodes are disposed to avoid overlap with a light-emitting region in the light-emitting layer as viewed from a light emitting direction.

Abstract: A multiple wavelength light emitting device is provided wherewith the resonance strength and directivity between colors can be easily adjusted for balance. This light emitting device comprises a light emission means 4 for emitting light containing wavelength components to be output, and a semi-reflecting layer group 2 wherein semi-reflecting layers 2R, 2G, and 2B that transmit some light having specific wavelengths emitted from the light emission means and reflect the remainder are stacked up in order in the direction of light advance in association with wavelengths of light to be output. Light emission regions AR, AG, and AB are determined in association with the wavelengths of light to be output.

Abstract: A light-emitting device having a light-emitting layer capable of emitting light by electroluminescence, a pair of anode and cathode for applying an electric field to the light-emitting layer, and an optical element for causing light generated in the light-emitting layer to be transmitted in a predetermined direction. The optical element forms an incomplete photonic band capable of inhibiting spontaneous emission of light in one dimension or two dimensions and includes first and second medium layers. Light generated in the light-emitting layer is emitted by inhibiting spontaneous emission in two dimensions by a first optical element and a second optical element.

Abstract: A light emitting device in accordance with the present invention has a substrate and a light-emitting element section formed on the substrate. The light-emitting element section includes a light-emitting layer, which is capable of generating light by electroluminescence, and an anode and cathode for applying an electrical field to that light-emitting layer. The anode and cathode includes a layer formed of a ferromagnetic material and are also magnetized.

Abstract: The invention provides an optical switch using a two-dimensional photonic crystal capable of enabling higher integration, an optical communications device and an optical communications system. An optical switch of the present invention can include a substrate, a first slab layer and a second slab layer disposed over the substrate, a third slab layer provided over the substrate and placed between the first slab layer and the second slab layer, and a phase control area provided for the first slab layer and capable of controlling the phase of light passing through the slab layer. The slab layers can include a two-dimensional photonic crystal structure, a linear defect which functions as a waveguide, a point defect for emitting light and a point defect for trapping light. The point defect for trapping light in each of the first slab layer and the second slab layer and the point defect for emitting light in the third slab layer are positioned so as to face each other.

Abstract: The light-emitting device has a substrate, an anode, an organic light-emitting layer, a cathode, a first and second gratings (optical sections). The first grating has a one-dimensional periodic refractive index distribution in the X direction and is capable of forming a photonic band gap. The second grating has a one-dimensional periodic refractive index distribution in the Y direction and is capable of forming a photonic band gap. A defect section is provided either for the first or second grating. This defect section is designed so that the energy level caused by the defect in within a prescribed emission spectrum. The organic light-emitting layer can emit light by electrically pumping, and an electric field is produced by the anode and cathode. The light-emitting device utilizes a two-dimensional photonic band gap and produces light with an extremely narrow spectral width at very high efficiency.

Abstract: An edge-emitting type light-emitting device (11000, 14000) comprises an organic light-emitting layer (40), a pair of electrode layers (30) and (50) for applying an electric field to the organic light-emitting layer (40), and an optical waveguide which transmits light emitted from the organic light-emitting layer (40) to the edge. The optical waveguide comprises a core layer (20) mainly transmitting light, and cladding layers (10) and (60) having a refractive index lower than that of the ecore layer (20). The core layer (20) may be a layer different from the organic light-emitting layer (40) or may comprise the organic light-emitting layer. A grating (12) is formed in the core layer (20) or in the boundary area between the core layer (20) and the cladding layer (10). A light-emitting device (31000) may comprise an optical fibre section (200). Another embodiment (43000) may comprise a defect and a grating having a one-dimensional periodic refractive index distribution and constituting a photonic band gap.

Abstract: The invention provides an optical multiplexing and demultiplexing device using a two-dimensional photonic crystal, in which miniaturization and higher integration thereof can be achieved; an optical communication apparatus; and an optical communication system. The optical multiplexing and demultiplexing device of the present invention includes a substrate; and a plurality of slab layers provided on the substrate. The slab layers each have a two-dimensional photonic crystal structure, in which low refractive index regions are periodically arranged. In addition, the slab layers have line defects, provided in part of the periodical arrangement so as to function as a waveguide, and at least point defects formed in the respective periodic arrangements, the point defects capturing light having a specific wavelength and introducing it to the line defects or capturing light having a specific wavelength from the line defects and radiating it.

Abstract: An efficient multiple-wavelength light emitting device is provided. This multiple-wavelength light emitting device comprises a light emitting layer 4 for emitting light containing wavelength components to be output, a negative electrode 5 that is positioned at the back surface of the light emitting layer and that transmits at least a portion of the light, reflecting layers 7R, 7G, and 7B, positioned at the back surface of the negative electrode, for reflecting, of the light emitted through the negative electrode to the back surface, light having specific wavelengths, which reflecting layers are stacked up in order perpendicularly to the light axis, in correspondence with the wavelengths of the light to be reflected, thus configuring a reflecting layer group 7. In the direction perpendicular to the light axis, divisions are made in any of at least two or more light emission regions which reflect light of different wavelengths.

Abstract: A surface-emitting device has a substrate and a light-emitting device section formed on the substrate, and emits light in a direction intersecting the substrate. The light-emitting device section includes a light-emitting layer, an anode and cathode for applying an electrical field to the light-emitting layer, and a grating.

Abstract: A directional coupler of the present invention includes a substrate; a first waveguide layer; a second waveguide layer disposed over the first waveguide layer; a separation layer which separates the first waveguide layer and the second waveguide layer at least at one end; and an optical coupling section which is a predetermined region in which the first waveguide layer and the second waveguide layer approach or come in contact with each other. Each of the first waveguide layer and the second waveguide layer is integrally and continuously formed.