Abstract: An optical imaging device and an optical sensor thereof are described. The optical sensor is used for sensing a signal light. The optical sensor includes a plurality of photosensitive pixels and at least one absorption wall. The absorption wall is disposed between the photosensitive pixels, and a top of the absorption wall is higher than photosensitive surfaces of the photosensitive pixels. Herein, the photosensitive pixels are used for receiving an incident signal light, and the absorption wall is used for absorbing non-parallel light components in the signal light.

Abstract: An optical recording medium includes a) a dielectric layer, b) a recording layer, and c) a reflective layer, which are stacked on a surface of a substrate in the described order or stacked on the surface in the order of b) the recording layer, a) the dielectric layer, and c) the reflective layer. The recording layer contains a mixed nickel oxides which decomposes to release a gas and becomes transparent upon heating.

Abstract: An optical recording medium includes a) a dielectric layer, b) a recording layer, and c) a reflective layer, which are stacked on a surface of a substrate in the described order or stacked on the surface in the order of b) the recording layer, a) the dielectric layer, and c) the reflective layer. The recording layer contains a mixed nickel oxides which decomposes to release a gas and becomes transparent upon heating.

Abstract: This invention relates to a method for detecting and compensating the disk tilt of an optical disk and an apparatus using it. The disk tilt causes the coma which degrades the carrier-to-signal ratio of a pickup. To reduce the coma induced by the disk tilt of an optical disk, the pickup of the present invention adapts a two-dimension (2-D) grating to produce a plurality of laser beams for detecting the disk tilt in the radial and tangential direction of the optical disk. In addition, according to the radial and tangential tilts of the disk, an actuation device adjusts a reflection angle of a reflective mean to change the incident angles of the laser beams for the compensation of the coma induced by the disk tilt of the optical disk.

Abstract: A bifocal optical pickup head is disclosed for use in a optical pickup apparatus having a single objective lens, for generating two different focuses (bifocus) to access a compact disc (CD) and a digital versatile disc (DVD), which the thickness is different. When a beam passes through an optical element disclosed in the present invention, numerical aperture is controlled and spherical aberration is reduced by the optical element due to variations in optical path and radius. Therefore, after beams having different numerical apertures are focused by an objective lens, various focuses can be obtained.

Abstract: The present invention pertains to a structure of pick-up head and its method for accessing signals, which operates in coordination with a disk made by ferroelectric material. An electric field is generated around the ends of two conductive wires by exerting a voltage on the wires. When the ends of the two wires are being close to the disk, the electric field polarizes the data-storing surface, which is formed by the ferroelectric material, so as to reach the function of writing. And as reading is needed, the two wires are also utilized of being induced by the electric lines of polarized area on the ferroelectric material to solve the data signals stored on the disk. Because the structure of pick-up head is simple and it is able to generate a smaller effective electric field, it is advantaged for the trend of miniaturization of pick-up head and capable of increasing the density of data on the disk.

Abstract: A polarized-dependent optical diffraction device includes a circular polarization beam generator and a diffraction grating. A diffraction grating is formed by a circular birefractive sheet having a corrugated surface with at least each groove filled with a mass of a material of a refractive index which is substantially equal to one of the circular birefractive indices. A circular polarization beam is supplied to the diffraction grating that the circularly-polarized beams traveling in both directions along a specific optical axis have different diffraction effects so as to enhance the utilization efficiency of the light. In particular, an external magnetic field is used to change the circular birefractive indices in such a manner diffraction efficiency is changed, featuring the merit of adjustability.

Abstract: A bifocal optical pickup head is disclosed for use in a optical pickup apparatus having a single objective lens, for generating two different focuses (bifocus) to access a compact disc (CD) and a digital versatile disc (DVD), which the thickness is different. When a beam passes through an optical element disclosed in the present invention, numerical aperture is controlled and spherical aberration is reduced by the optical element due to variations in optical path and radius. Therefore, after beams having different numerical apertures are focused by an objective lens, various focuses can be obtained.

Abstract: The present invention is an optical pick-up head with a single objective lens, which discloses an optical pick-up head that can retrieve data from CD and DVD with different thickness using a single objective lens and a special optical element on the optical path of the optical pick-up head. This optical element is a three-beam grating which is formed a reflective film thereon, for example, by coating a metal or dielectric layer to achieve the goal of controlling the numerical aperture. Thus, this invention provides a single objective lens optical pick-up head with simple structure, low cost, easy assembling, and applications to multi-wavelength systems.

Abstract: A bifocal optical pickup head is disclosed for use in a optical pickup apparatus having a single objective lens, for generating two different focuses (bifocus) to access a compact disc (CD) and a digital versatile disc (DVD), which the thickness is different. When a beam passes through an optical element disclosed in the present invention, numerical aperture is controlled and spherical aberration is reduced by the optical element due to variations in optical path and radius. Therefore, after beams having different numerical apertures are focused by an objective lens, various focuses can be obtained.