Patent application number | Description | Published |
20080316600 | WAVELENGTH-SELECTIVE DIFFRACTION ELEMENT AND OPTICAL HEAD DEVICE INCORPORATING THE SAME - The present invention provides a wavelength-selective diffraction element, configured such that light having a plurality of wavelengths are incident thereon as incident light, which is provided with: a transparent substrate; a concavo-convex part, formed on the transparent substrate such that concave portions and convex portions are cyclically extended in one direction, and comprised of a first material which is optically isotropic; and a filling part, filling at least the concave portions and comprised of a second material which is optically isotropic. The first material and the second material have no absorbance with respect to the wavelengths of the incident light. The first material and the second material have an identical refractive index with respect to light having a first wavelength which is at least one of the wavelengths of the incident light. The first material and the second material have different refractive indices with respect to light having a second wavelength which is at least one of the wavelengths of the incident light and different from the first wavelength. | 12-25-2008 |
20090016191 | OPTICAL HEAD DEVICE - It is provided an optical head device which includes: a light source; an objective lens, configured to converge light emitted from the light source to an information recording surface of an optical disk; a beam splitter, configured to deflect returned light reflected by the optical disk into an optical path which is different from an optical path of the light emitted from the light source; a photo detector, configured to detect the returned light deflected by the beam splitter; and a depolarizing element, disposed on an optical path between the beam splitter and the photo detector, and configured to cause the returned light to transmit through while reducing a degree of polarization of the returned light. | 01-15-2009 |
20090268585 | WAVELENGTH SELECTING WAVELENGTH PLATE AND OPTICAL HEAD DEVICE USING IT - An optical rotating plate has an optical rotating material layer. A phase plate is provided on a first surface side of the optical rotating plate and has at least one birefringent material layer. The first surface side is disposed toward an emitting side of an optical path, thereby giving different phase differences to a first linearly polarized light group containing at least a linearly polarized light having a first wavelength and a second linearly polarized light group containing at least a linearly polarized light having a second wavelength which is different from the first wavelength. | 10-29-2009 |
20120038934 | DIFFRACTIVE OPTICAL ELEMENT AND MEASURING DEVICE - To provide a diffractive optical element and a measuring device capable of generating light spots of dispersive type. The problem is resolved by providing a diffractive optical element having concaves and convexes and diffracting incident light in two dimensions so as to generate diffracted light, wherein when the number of a part of light spots formed by the diffracted light is denoted by n, an average distance W to the nearest neighbor in the light spots normalized by an area of a region onto which the light spots are projected falls within a range of 1/(2×n | 02-16-2012 |
20120105855 | DIFFRACTIVE OPTICAL ELEMENT AND MEASUREMENT INSTRUMENT - A diffractive optical element includes: a first diffractive element in which a plurality of basic units are two-dimensionally arranged; and a second diffractive element in which a plurality of basic units are two-dimensionally arranged, wherein when a direction in which the basic units are arranged in the first diffractive element is a first direction, a direction in which the basic units are arranged in the second diffractive element is a second direction, an angle φ between the first direction and the second direction is such that −|φ | 05-03-2012 |
20120112048 | COMPOSITE OPTICAL ELEMENT AND OPTICAL HEAD DEVICE - A composite optical element includes: a single lens; a first resin layer formed on a surface of the single lens; a second resin layer formed on the first resin layer, wherein: the first resin layer has a diffraction grating of a Fresnel lens configuration; and a refractive index of the first resin layer and that of the second layer are substantially the same value for at least a light beam of one of a light beam of a wavelength λ | 05-10-2012 |
20120207007 | REFLECTION TYPE WAVELENGTH PLATE AND OPTICAL HEAD DEVICE - A phase difference layer | 08-16-2012 |
20120287767 | DIFFRACTION GRATING, ABERRATION CORRECTION ELEMENT AND OPTICAL HEAD DEVICE - There is provided a diffraction grating including a convex portion and a concave portion which are used for lights having different wavelengths λ | 11-15-2012 |
20130182327 | DIFFRACTIVE OPTICAL ELEMENT AND MEASUREMENT DEVICE - Disclosed are a diffractive optical element and a measurement device that are capable of reliably suppressing occurrence of a zero-order diffracted light beam and generating light spots in a wide range. The diffractive optical element has concave and convex portions and diffracts incident light in two dimensions to generate diffracted light. When a maximum diffraction angle with reference to an optical axis of the incident light is an angle range θ, the angle range θ is 7.5° or greater, and diffraction efficiency in a zero-order diffracted light beam is 5% or less. | 07-18-2013 |