Sony Corporation

Nissan Motor Company Limited

Masaki Saitoh

Hitoshi Tamada

Atsuo Yamada

Chiharu Isobe

Hiroshi Yamashita

Tohru Doumuki

Tooru Kosemura

Yukie Taneyama

A die head apparatus is provided with a front blade, a rear blade, a center blade, and an internal impurity removal space. The front blade and the center blade are configured to form a pool of a slurry. The internal impurity removal space is positioned between the center blade and the rear blade. A distance separating the rear blade and the substrate is set to be smaller than the distance separating the center blade and the substrate.

Die head apparatus, coating method, and laminated body forming apparatus

An optical waveguide device for use as a second harmonic generator includes a nonlinear optical crystalline substrate of KTiOPO.sub.4 and an optical waveguide core of a dielectric material, such as Ta.sub.2 O.sub.5, disposed on the nonlinear optical crystalline substrate. The optical waveguide converts a fundamental wave having a wavelength .lambda. which is guided through the optical waveguide into a second harmonic wave having a wavelength .lambda./2, the second harmonic wave having the same polarization as the fundamental wave which is guided through the optical waveguide. The optical waveguide has a thickness of 190 nm or greater. The optical waveguide device also has a dielectric loaded strip disposed on the optical waveguide core. The dielectric loaded strip may be made of SiO.sub.2 or SiO.sub.2 doped with Ta.sub.2 O.sub.5. Alternatively, the optical waveguide may be a ridge-type optical waveguide, and the optical waveguide device may also has a cladding layer disposed on the nonlinear optical crystalline substrate and the optical waveguide core.

Optical waveguide device and second harmonic generator using the same

A heat treatment method heats an oxide optical crystal in an oxygen atmosphere containing ozone to improve the light absorption characteristics of the oxide optical crystal so that the light absorption of the oxide optical crystal with light in wavelength bands other than light in wavelength bands with which the oxide optical crystal exerts the intrinsic absorption is reduced to the least possible extent. Guided-optical-wave propagation devices and optical devices, such as optical isolators, optical recording media and second harmonic generators, employing the oxide optical crystal having these improved absorption characteristics, operate at a high efficiency.

Method of heat-treating an oxide optical crystal and a heat treatment

Disclosed herein is an optical waveguide device of LiNbO.sub.3 which guides efficiently both or either of ordinary ray and extraordinary ray of visible light in the short wavelength region. It is prepared by forming an LiNbO.sub.3 thin film optical waveguide on an LiNbO.sub.3 substrate undoped or doped with MgO, with or without a base layer interposed between them, by liquid phase epitaxy which employs Li.sub.2 O-B.sub.2 O.sub.3 as the flux.

LiNbO3 thin film optical waveguide device and process for producing the

An optical waveguide device is disclosed which comprises a KTiOPO.sub.4 single crystal substrate and an amorphous optical waveguide formed of Ta.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 doped with TiO.sub.2. A second harmonic generator device in the form of the Cerenkov radiation using the optical waveguide has high SHG efficiency. Since the Cerenkov angle can be made small by optimizing the dimensions, the spread angle of the SHG light can be made small.

Optical waveguide device and optical second harmonic generator using the

An optical waveguide, a dielectric device and method for fabricating such devices in which a substrate is polarized in a first direction and a dielectric thin film is formed on the surface of the substrate and polarized in the opposite direction to the substrate. Parallel grooves may be formed in the substrate. In one embodiment, a first dielectric thin film is formed on the substrate and is formed with grooves and is polarized in the same direction as the substrate. Then, a second dielectric thin film is formed over the first dielectric thin film and it is polarized in a direction which is opposite to the substrate and the first thin film.

Optical waveguide which is formed by liquid phase epitaxial growth

An optical waveguide apparatus arranged such that a Ta.sub.2 O.sub.5 -TiO.sub.2 system amorphous thin film is formed on a substrate. This optical waveguide apparatus can perform optical waveguiding at high efficiency. Also, an optical waveguide-type second harmonic generator of Cerenkov radiation type arranged such that the amorphous thin film is formed on a non-linear optical crystal substrate. This optical waveguide-type second harmonic generator can efficiently perform the confinement of light, whereby a fundamental wave of near-infrared rays can be received and a second harmonic wave radiated to the substrate side can be obtained with high efficiency. Further, in a second harmonic generator (SHG) in which the amorphous optical waveguide is formed on an LiNbO.sub.3 non-linear optical crystal substrate on which surface is formed a periodically-poled region, this second harmonic generator can very efficiently generate a light having a wavelength of half of a semiconductor laser light of 0.8 micrometer band by selecting a relationship between a periodically-poled region cycle .LAMBDA. and a thickness h of an optical waveguide.

Growing community of inventors

Kanagawa, Japan

Masaki Saitoh