Abstract: An image display device and an image display system which can establish visible light communication without interfering with an image displayed at a predetermined frame rate are provided. A controller 12 controls a spatial light modulator in accordance with an image signal to display the image, and also modulates an intensity of a visible light output from a backlight 13 with a frequency higher than the frame rate of the image signal to have the visible light output from the backlight 13 carry additional information. A light receiver 15 receives the visible light and demodulates to extract the additional information. An additional information generator 16 outputs the additional information.

Abstract: A method for producing a high-quality group-III element nitride crystal at a high crystal growth rate, and a group-III element nitride crystal are provided. The method includes the steps of placing a group-III element, an alkali metal, and a seed crystal of group-III element nitride in a crystal growth vessel, pressurizing and heating the crystal growth vessel in an atmosphere of nitrogen-containing gas, and causing the group-III element and nitrogen to react with each other in a melt of the group-III element, the alkali metal and the nitrogen so that a group-III element nitride crystal is grown using the seed crystal as a nucleus. A hydrocarbon having a boiling point higher than the melting point of the alkali metal is added before the pressurization and heating of the crystal growth vessel.

Abstract: The present invention provides an acoustooptic device usable even with light in the ultraviolet region, free from laser damage and optical damage, and excellent in acoustooptic performance and an optical imaging apparatus using the same. The acoustooptic device according to the present invention includes a high-frequency signal input part (65), a transducer part (64), and an acoustooptic medium (6). A high-frequency signal input from the high-frequency signal input part (65) is converted into a mechanical vibration by the transducer part (64), and an optical characteristic of the acoustooptic medium (6) varies depending on the mechanical vibration. The acoustooptic medium is formed of a Group III nitride crystal. The optical imaging apparatus according to the present invention includes a light source, an acoustooptic device, a driving circuit, and an image plane.

Abstract: An image display device and an image display system which can establish visible light communication without interfering with an image displayed at a predetermined frame rate are provided. A controller 12 controls a spatial light modulator in accordance with an image signal to display the image, and also modulates an intensity of a visible light output from a backlight 13 with a frequency higher than the frame rate of the image signal to have the visible light output from the backlight 13 carry additional information. A light receiver 15 receives the visible light and demodulates to extract the additional information. An additional information generator 16 outputs the additional information.

Abstract: An object of the present invention is to effectively add Ge in the production of GaN through the Na flux method. In a crucible, a seed crystal substrate is placed such that one end of the substrate remains on the support base, whereby the seed crystal substrate remains tilted with respect to the bottom surface of the crucible, and gallium solid and germanium solid are placed in the space between the seed crystal substrate and the bottom surface of the crucible. Then, sodium solid is placed on the seed crystal substrate. Through employment of this arrangement, when a GaN crystal is grown on the seed crystal substrate through the Na flux method, germanium is dissolved in molten gallium before formation of a sodium-germanium alloy. Thus, the GaN crystal can be effectively doped with Ge.

Abstract: An object of the present invention is to obtain, with respect to a semiconductor light-emitting element using a group III nitride semiconductor substrate, a semiconductor light-emitting element having an excellent light extraction property by selecting a specific substrate dopant and controlling the concentration thereof. The semiconductor light-emitting element comprises a substrate composed of a group III nitride semiconductor comprising germanium (Ge) as a dopant, an n-type semiconductor layer composed of a group III nitride semiconductor formed on the substrate, an active layer composed of a group III nitride semiconductor formed on the n-type semiconductor layer, and a p-type semiconductor layer composed of a group III nitride semiconductor formed on the active layer in which the substrate has a germanium (Ge) concentration of 2×1017 to 2×1019 cm?3.

Abstract: A method for producing Group-III-element nitride crystals by which an improved growth rate is obtained and large high-quality crystals can be grown in a short time, a producing apparatus used therein, and a semiconductor element obtained using the method and the apparatus are provided. The method is a method for producing Group-III-element nitride crystals that includes a crystal growth process of subjecting a material solution containing a Group III element, nitrogen, and at least one of alkali metal and alkaline-earth metal to pressurizing and heating under an atmosphere of a nitrogen-containing gas so that the nitrogen and the Group III element in the material solution react with each other to grow crystals.

Abstract: A method for manufacturing Group III nitride crystals with high quality is provided. By the method, a crystal raw material solution and gas containing nitrogen are introduced into a reactor vessel, which is heated, and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device to the reactor vessel through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel, impurities attached to the pressure-resistant vessel and the like into the crystal growing site can be prevented. Further, the gas flows through the reactor vessel, to suppress aggregation of an evaporating alkali metal, etc., at the gas inlet and reduce flow of the metal vapor into the gas supplying device.

Abstract: A manufacturing method of a semiconductor element provided with a semiconductor layer containing a crystal of an organic semiconductor material of the invention includes the steps of (i) forming a frame (12) on a substrate (base) (11), and (ii) forming the semiconductor layer (crystal (13)) inside the frame (12). The step (ii) includes a crystal forming step in which a solution (21) containing the organic semiconductor material and a liquid medium is placed inside the frame (12) and then the crystal (13) is formed from the solution (21).

Abstract: A method for producing a high-quality group-III element nitride crystal at a high crystal growth rate, and a group-III element nitride crystal are provided. The method includes the steps of placing a group-III element, an alkali metal, and a seed crystal of group-III element nitride in a crystal growth vessel, pressurizing and heating the crystal growth vessel in an atmosphere of nitrogen-containing gas, and causing the group-III element and nitrogen to react with each other in a melt of the group-III element, the alkali metal and the nitrogen so that a group-III element nitride crystal is grown using the seed crystal as a nucleus. A hydrocarbon having a boiling point higher than the melting point of the alkali metal is added before the pressurization and heating of the crystal growth vessel.

Abstract: A method for producing a GaN crystal capable of achieving at least one of the prevention of nucleation and the growth of a high-quality non-polar surface is provided. The production method of the present invention is a method for producing a GaN crystal in a melt containing at least an alkali metal and gallium, including an adjustment step of adjusting the carbon content of the melt, and a reaction step of causing the gallium and nitrogen to react with each other. According to the production method of the present invention, nucleation can be prevented, and as shown in FIG. 4, a non-polar surface can be grown.

Abstract: A 2-dimensional beam scan unit (2) reflects emission beams from a red laser light source (1a), a green laser light source (1b) and a blue laser light source (1c) and scans in a 2-dimensional direction. Diffusion plates (3a, 3b, 3c) diffuse the respective light beams scanned in the 2-dimensional direction to introduce them to corresponding spatial light modulation elements (5a, 5b, 5c). The respective spatial light modulation elements (5a, 5b, 5c) modulate the respective lights in accordance with video signals of the respective colors. A dichroic prism (6) multiplexes the lights of the three colors after the modulation and introduces the multiplexed lights to a projection lens (7) so that a color image is displayed on a screen (8).

Abstract: A nitride single crystal is produced on a seed crystal substrate 5 in a melt containing a flux and a raw material of the single crystal in a growing vessel 1. The melt 2 in the growing vessel 1 has temperature gradient in a horizontal direction. In growing a nitride single crystal by flux method, adhesion of inferior crystals onto the single crystal is prevented and the film thickness of the single crystal is made constant.

Abstract: An object of the present invention is to realize, by the flux process, the production of a high-quality n-type semiconductor crystal having high concentration of electrons. The method of the invention for producing an n-type Group III nitride-based compound semiconductor by the flux process, the method including preparing a melt by melting at least a Group III element by use of a flux; supplying a nitrogen-containing gas to the melt; and growing an n-type Group III nitride-based compound semiconductor crystal on a seed crystal from the melt. In the method, carbon and germanium are dissolved in the melt, and germanium is incorporated as a donor into the semiconductor crystal, to thereby produce an n-type semiconductor crystal. The mole percentage of germanium to gallium in the melt is 0.05 mol % to 0.5 mol %, and the mole percentage of carbon to sodium is 0.1 mol % to 3.0 mol %.

Abstract: After forming domain inverted layers 3 in an LiTaO3 substrate 1, an optical waveguide is formed. By performing low-temperature annealing for the optical wavelength conversion element thus formed, a stable proton exchange layer 8 is formed, where an increase in refractive index generated during high-temperature annealing is lowered, thereby providing a stable optical wavelength conversion element. Thus, the phase-matched wavelength becomes constant, and variation in harmonic wave output is eliminated. Consequently, with respect to an optical wavelength conversion element utilizing a non-linear optical effect, a highly reliable element is provided.

Abstract: A production method is provided that enables to produce a large-sized bulk silicon carbide (SiC) crystal of high quality at low cost. A large-sized bulk silicon carbide (SiC) crystal of high quality can be obtained at a lower temperature by reacting silicon (Si) and carbon (C) produced from a lithium carbide such as dilithium acetylide (Li2C2) with each other in an alkali metal melt and thereby producing or growing a silicon carbide (SiC) crystal. FIG. 17 shows a high-resolution TEM (HR-TEM) image of the resultant 2H—SiC crystal. A preferable lithium carbide is dilithium acetylide (Li2C2). A preferable alkali metal melt is a melt of lithium alone.

Abstract: A manufacturing method of a semiconductor element provided with a semiconductor layer containing a crystal of an organic semiconductor material of the invention includes the steps of (i) forming a frame (12) on a substrate (base) (11), and (ii) forming the semiconductor layer (crystal (13)) inside the frame (12). The step (ii) includes a crystal forming step in which a solution (21) containing the organic semiconductor material and a liquid medium is placed inside the frame (12) and then the crystal (13) is formed from the solution (21).

Abstract: After forming domain inverted layers 3 in an LiTaO3 substrate 1, an optical waveguide is formed. By performing low-temperature annealing for the optical wavelength conversion element thus formed, a stable proton exchange layer 8 is formed, where an increase in refractive index generated during high-temperature annealing is lowered, thereby providing a stable optical wavelength conversion element. Thus, the phase-matched wavelength becomes constant, and variation in harmonic wave output is eliminated. Consequently, with respect to an optical wavelength conversion element utilizing a non-linear optical effect, a highly reliable element is provided.

Abstract: In a coherent light source in which limitations on the wavelength of emitted light are relaxed, a coherent light source for simultaneously emitting a first light (3) and a second light (4) having a wavelength shorter than that of the first light (3), includes: a light source main body emitting at least the first light (3); a mirror (5) which transmits or reflects the first light (3); and a functional film (6) provided on at least a part of the mirror (5). The functional film (6) has a photocatalytic effect to be induced by the second light (4).

Abstract: The present invention provides a manufacturing method that makes it possible to manufacture a substrate that is formed of high-quality Group III nitride crystals alone and has less warping. A Group III nitride layer (a seed layer and a selective growth layer) including gaps is formed on a substrate (a sapphire substrate). In an atmosphere containing nitrogen, the surface of the Group III nitride layer is brought into contact with a melt containing alkali metal and at least one Group III element selected from gallium, aluminum, and indium, and thereby the at least one Group III element and the nitrogen are made to react with each other to grow Group III nitride crystals (GaN crystals) on the Group III nitride layer. Thereafter, a part including the substrate and a part including the Group III nitride crystals are separated from each other in the vicinities of the gaps.