Sharp Kabushiki Kaisha Corporation

Shinya Hirata

Yoshitaka Tomomura

Masahiko Kitagawa

Akira Takahashi

Yoshiteru Murakami

Kenji Nakanishi

Go Mori

Naoyasu Iketani

Ippei Suzuki

An optical disk is provided with a recording layer, and with an optical coupling layer on a light-incident side of the recording layer. An optical recording and reproducing device and method include an objective lens and a hemispherical lens, which converge a light beam from a light source and project the light beam onto the optical disk. The hemispherical lens is provided in close proximity to the optical coupling layer, in a position such that an interval therebetween is not more than the wavelength of the light produced by the light source. The light beam converged by the objective lens and the hemispherical lens is coupled with the optical coupling layer while substantially maintaining a direction of propagation in which it was propagating while inside the hemispherical lens.

Optical recording and reproducing method optical recording and reproducing device, and optical recording medium

A method for fabricating a semiconductor thin film is disclosed. The method includes the step of epitaxially growing a semiconductor layer made of a group II-VI compound semiconductor to have a thickness of at least one atomic layer or more, on a main plane of a single-crystal semiconductor substrate, the semiconductor substrate having one of a diamond structure and a zinc blende structure, the main plane being inclined by an angle in the range of 2 to 16 degrees with respect to a (100) plane.

Method for producing a group II-VI compound semiconductor thin film and

A semiconductor waveguide structure of the II-VI group compound semiconductor made of the II group element and the VI group element. The waveguide structure includes a waveguide layer and clad layers which puts the waveguide layer therebetween. The waveguide layer has a refractive index larger than a refractive index of each clad layer. At least one of the clad layers contains the element Cd. With such an arrangement, the refractive index of one clad layer is established to be different from that of the other clad layer. In such a case, it is preferable that the semiconductor waveguide structure comprises at least two waveguide layers which are adjacent to each other and that the structure has either one of the features as follows: each refractive index of the waveguide layers varies stepwise at each boundary surface of the layers; the refractive index of at least one of the waveguide layers varies so as to be inclined; and super lattice layers are formed between the clad layer and the waveguide layers. Further, in the arrangement, more than two waveguide layers and clad layers may be formed in such a manner that each of the waveguide layer is put between the clad layers.

Semiconductor waveguide structure of a II-VI group compound

Growing community of inventors

Tenri, Japan

Shinya Hirata