摘要:
A diffraction element is disposed between a beam branching element (such as a beam splitter) and a photodetector. The diffraction element further segment an interference fringe introduced into stray light by a diffraction grating which divides a laser beam emitted from a laser beam source into a main beam and two sub-beams.
摘要:
A laser beam emitted from a light source is divided into a main beam and two sub-beams by a diffraction grating. A filter is arranged between a collimator lens and an objective lens. A filter unit is arranged in a predetermined pattern in the filter. The filter unit gives a maximum transmittance or a maximum reflectance at an incident angle at which the laser beam is incident in a parallel light state. The filter unit is formed in a pattern in which at least the laser beam reflected from a layer except a recording layer of an irradiation target is prevented from entering a sub-beam sensor pattern.
摘要:
A diffraction element is disposed between a beam branching element (such as a beam splitter) and a photodetector. The diffraction element further segment an interference fringe introduced into stray light by a diffraction grating which divides a laser beam emitted from a laser beam source into a main beam and two sub-beams.
摘要:
An optical element is disposed on an optical path between a beam branching element and a photodetector. The optical element is disposed at a focal position of a stray light beam reflected by a recording layer except a target recording layer, and shields or attenuates the light beam in a region where the stray light beam converges.
摘要:
An optical element is disposed on an optical path between a beam branching element and a photodetector. The optical element is disposed at a focal position of a stray light beam reflected by a recording layer except a target recording layer, and shields or attenuates the light beam in a region where the stray light beam converges.
摘要:
The object is to provide a method and device to detect internal defect in the weld overlaid portion of erosion resistant material in the border portion between the blade profile and the shroud of a turbine blade with high accuracy by a static test method for an individual turbine blade applying a resultant pressing force, corresponding to centrifugal force and untwisting force of the turbine blade 10 in operation of the turbine, to the shroud 12 with installing the blade root 18 of the turbine blade 10 to the blade root retainer 20 and applying a force in the direction of centrifugal force on the blade root 18 from outside of the blade root retainer 20 to eliminate backlash between the blade root 18 and blade root retainer 20, retaining securely the shroud 12 on the side opposite to the portion which is applied the pressing force, and implementing simulated test of centrifugal stress in the weld-overlaid portion by applying the resultant pressing force, corresponding to centrifugal force and untwisting force of the turbine blade 10 in operation of the turbine, to the shroud 12.
摘要:
A method of manufacturing an element having a microstructure of an excellent grating groove pattern or the like is obtained. This method of manufacturing an element having a microstructure comprises steps of forming a metal layer on a substrate, forming a dot column of concave portions on the surface of the metal layer and anodically oxidizing the surface of the metal layer formed with the dot column of concave portions while opposing this surface to a cathode surface thereby forming a metal oxide film having a grating groove pattern. When the interval between the concave portions of the dot column is reduced, therefore, a linear grating groove pattern having a large depth with a uniform groove width along the depth direction is easily formed in a self-organized manner.
摘要:
A semiconductor laser device includes a Si(100) substrate in which a recess having an opening and a bottom face surrounded by inner wall surfaces is formed, a semiconductor laser element placed on the bottom face, and a translucent sealing glass, mounted on top of the Si(100) substrate, which seals the opening. The laser light emitted from the semiconductor laser element is reflected by a metallic reflective film formed on the inner wall surface and then transmits through the sealing glass so as to be emitted externally.
摘要:
A method of manufacturing an element having a microstructure of an excellent grating groove pattern or the like is obtained. This method of manufacturing an element having a microstructure comprises steps of forming a metal layer on a substrate, forming a dot column of concave portions on the surface of the metal layer and anodically oxidizing the surface of the metal layer formed with the dot column of concave portions while opposing this surface to a cathode surface thereby forming a metal oxide film having a grating groove pattern. When the interval between the concave portions of the dot column is reduced, therefore, a linear grating groove pattern having a large depth with a uniform groove width along the depth direction is easily formed in a self-organized manner.
摘要:
First and second photodiodes are arranged on the upper surface of a stem, returned light beams diffracted in the + 1st order by a transmission type holographic optical element are received by the first photodiode, while returned light beams diffracted in the − 1st order are received by the second photodiode. The first photodiode has a plurality of light receiving regions, and respectively outputs a reproducing signal, a focus error signal and a tracking error signal on the basis of the returned light beams. On the other hand, the second photodiode has a single light receiving region, and outputs a reproducing signal on the basis of the returned light beams.