摘要:
Disclosed is an optical system for an optical disk drive for reading/writing data from/in an optical disk. The optical system includes a light source emitting a parallel laser beam, a deflector having a rotatable mirror surface. The parallel laser beam emitted by the light source is incident on the mirror surface of the deflector and is deflected towards an objective lens system which faces the optical disk. A relay lens system is provided between the deflector and the objective lens system such that the mirror surface and a front principal plane of the objective lens system have a substantially conjugate relationship.
摘要:
An optical disc apparatus includes a fixed portion having a light source portion and a movable portion that holds an objective lens and moves along a radial direction of an optical disc. The fixed portion includes the light source portion for selectively emitting short and long wavelength laser beams, and a collimator lens for collimating the laser beams. The objective lens includes a positive refractive lens and a diffractive lens structure formed on a surface of the refractive lens. The diffractive lens structure has wavelength dependence such that spherical aberration varies in the undercorrected direction as wavelength of incident light increases. The objective lens converges the short wavelength laser beam of a predetermined diffraction order onto an informatlon layer of a thin cover type optical disc, and converges the long wavelength laser beam of the identical diffraction order onto an information layer of a thick cover type optical disc.
摘要:
An optical head is provided with a beam splitting element which divides a beam reflected by a data recording surface of an optical disc into two beams with generating opposite defocus therebetween, and a pair of light receiving elements which receive the two beams divided by the beam splitting element, respectively, the pair of light receiving elements being arranged substantially on a same plane. A light receiving surface of each of the pair of light receiving elements is divided, by two lines extending in a direction corresponding to a tracking direction on the optical disc, into at least three light receiving areas. A focusing error signal is generated in accordance with outputs of the at least three light receiving areas.
摘要:
An X-ray waveguide for propagation of an X-ray therethrough includes a core and a cladding. The core has a periodic structure in which plural substances having different refractive-index real parts are periodically arrayed in a direction perpendicular to an X-ray guiding direction. Given that a maximum length of the core in the X-ray guiding direction is l, a maximum thickness of the core is t, and a Bragg angle of the periodic structure for the X-ray is θB(°), at least one end surface of a core region in the X-ray guiding direction is inclined at an inclination angle φ(°), which satisfies tan−1(t/l)
摘要:
Provided is an X-ray mirror, a method of producing the X-rat mirror, and an X-ray apparatus. The X-ray mirror comprises: a substrate; and an X-ray reflecting structure formed of multiple regions present on the substrate, in which the X-ray reflecting structure comprises a mesostructured film that has the multiple regions having different structural periods in a normal direction of the substrate. Thus, there can be reduced the absorption loss of an X-ray of the mirror that reflects X-rays having different energies.
摘要:
An X-ray waveguide includes a cladding and a core. The core has a periodic structure formed in at least one period direction. The periodic structure includes periodically arranged members made of material having different refractive index real parts. The core is surrounded by the cladding in the plane perpendicular to a wave-guiding direction. The Bragg angle obtained from the periodicity of the periodic structure is smaller than the total reflection critical angle at which X-rays are incident on the interface between the cladding and the core. The at least one period direction is the direction of at least one fundamental vector expressing the periodicity of the periodic structure in a plane of the core perpendicular to the wave-guiding direction.
摘要:
An X-ray monochromator including: a substrate having a concave surface; and an inorganic oxide film formed on the concave surface and having a plurality of pores, in which the plurality of pores of the inorganic oxide film being laid periodically in a stacked manner in the normal directions of the concave surface, and in which the plurality of pores being cylindrical is provided. The X-ray monochromator shows an excellent X-ray spectroscopic performance.
摘要:
Information regarding a base sequence of a target nucleic acid is acquired by preparing a sample comprising the target nucleic acid hybridized with a primer or a sample comprising the target nucleic acid containing a promoter sequence, a polymerase, a nucleotide derivative having an electrochemically convertible moiety; allowing the three components to coexist in a solvent; and detecting whether the nucleotide derivative is introduced into the primer or a transcription product of the target nucleic acid or not using an electrochemical reaction.
摘要:
A single-element objective lens for an optical pick-up is configured to converge substantially parallel light rays incident thereon onto a data recording surface of an optical recording medium. The objective lens includes, a first surface, which is a light incident side surface, and a second surface, which is an optical recording medium side surface. The first surface is an aspherical surface having a positive power, and the second surface is an aspherical surface having positive or negative power. The objective lens is designed such that paraxial wavefront aberration is 0.07&lgr; rms or less when a decentering amount between the first and second surfaces is 2 &mgr;m or less so as to converge the incident light substantially to a diffraction limit. A numerical aperture of the objective lens is 0.8 or more.
摘要:
A photomagnetic head apparatus includes a beam splitter which splits a laser beam, reflected by concentric recording tracks of a rotating photomagnetic recording disc, into three bundles of rays. The three bundles of rays have different polarization directions in a plane which lies in a radial direction of the recording tracks. One of the three bundles of rays is used as a servo-signal light, and the remaining two bundles of rays are used as data signal lights. A defocusing diffraction element splits at least the servo-signal light into a least two bundles of rays in a direction corresponding to the tangential direction of the recording tracks, substantially perpendicular to the split direction of the beam splitter and which provides at least two split lights with a predetermined amount of positive or negative defocus in an optical axis direction. A pair of servo-signal light receiving elements receive the split beams of the servo-signal light produced by the defocusing diffraction element. A data light receiving element receives the data signal lights. The defocusing diffraction element is made of a non-circular element whose numerical aperture in the tangential direction of the recording tracks is smaller than the numerical aperture in the radial direction.