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US 7,466,487 B2Granted
Light diffraction method and diffraction device, diffraction grating used for them, and position encoder device
AssigneesJapan Science and Technology Agency, National Institute for Materials Science
InventorsHideki Miyazaki, Hiroshi Miyazaki, Kenjiro Miyano
Life of this patent
Estimating the term…
Abstract
A principle of blazing that is effective even in the resonance domain. Light (51) is made incident on a diffraction grating so that specular resonance can occur in two or more light scattering units including, for example, bispheres (11a, 21a; 12a,22a), and by the specular resonance, a fraction of diffracted light 52 that is diffracted by the first layer (1) and the second layer (2) is selectively enhanced. It also becomes possible to tune a blazing condition by a control signal from outside.
Claims15
A light diffraction method using a diffraction grating, wherein:
- the diffraction grating comprises:
- a first layer containing two or more first light scatterers, two or more of which being periodically arrayed along a first direction and either a) two or more of which being arrayed along a second direction or b) extending along the second direction;
- and
- a second layer containing two or more second light scatterers respectively corresponding to the two or more first light scatterers, the two or more second light scatterers being disposed at positions shifted from the two or more first light scatterers by a predetermined distance along a predetermined direction in a plane that is other than a plane containing the first direction and the second direction;
- the method comprising:
- making light incident on the diffraction grating so that:
- in a case of a), the light is incident along a plane containing two or more trajectories selected from trajectories formed by the shifting of the two or more first light scatterers in the predetermined direction;
- and
- in both cases of a) and b), specular resonance occurs in two or more light scattering units, each comprising one light scatterer selected from the two or more first light scatterers and one of the second light scatterers corresponding to the selected one of the first light scatterers,
- whereby a fraction of diffracted light that is diffracted by the first layer and the second layer is enhanced selectively by the specular resonance in the two or more light scattering units.
7 more elements
A light diffraction device comprising:
- a diffraction grating and a light projecting device, the diffraction grating comprising:
- a first layer containing two or more first light scatterers, two or more of which being periodically arrayed along a first direction and either a) two or more of which being arrayed along a second direction or b) extending along the second direction;
- and
- a second layer containing two or more second light scatterers respectively corresponding to the two or more first light scatterers, the two or more second light scatterers being disposed at positions shifted from the two or more first light scatterers by a predetermined distance along a predetermined direction in a plane that is other than a plane containing the first direction and the second direction;
- the light projecting device being for making light incident on the diffraction grating so that:
- in a case of a), the light is incident along a plane containing two or more trajectories selected from trajectories formed by the shifting of the two or more first light scatterers in the predetermined direction;
- and
- in both cases of a) and b), specular resonance occurs in two or more light scattering units, each comprising one light scatterer selected from the two or more first light scatterers and one of the second light scatterers corresponding to the selected one of the first light scatterers,
- whereby a fraction of diffracted light that is diffracted by the first layer and the second layer is selectively enhanced by the specular resonance in the two or more light scattering units.
6 more elements
A diffraction grating comprising:
- a first layer containing two or more first light scatterers, two or more of which being periodically arrayed along a first direction and either two or more of which being arrayed along a second direction or extend along the second direction;
- and
- a second layer containing two or more second light scatterers respectively corresponding to the two or more first light scatterers, the two or more second light scatterers being disposed at positions shifted from the two or more first light scatterers by a predetermined distance along a predetermined direction in a plane that is other than a plane containing the first direction and the second direction;
- wherein the diffraction grating has two or more light scattering units, in each of which one light scatterer selected from the two or more first light scatterers and one of the second light scatters corresponding to the selected one of the first light scatters are disposed adjacent to each other so that incident light can cause specular resonance;
- and
- the two or more first light scatterers and the two or more second light scatterers respectively in the first layer and the second layer are disposed spaced apart from each other.
3 more elements
A diffraction grating comprising:
- a first layer containing two or more first light scatterers, two or more of which being periodically arrayed along a first direction and either two or more of which being arrayed along a second direction or extend along the second direction;
- and
- a second layer containing two or more second light scatterers respectively corresponding to the two or more first light scatterers, the two or more second light scatterers being disposed at positions shifted from the two or more first light scatterers by a predetermined distance along a predetermined direction in a plane that is other than a plane containing the first direction and the second direction;
- wherein the diffraction grating has two or more light scattering units, in each of which one light scatterer selected from the two or more first light scatterers and one of the second light scatters corresponding to the selected one of the first light scatters are disposed adjacent to each other so that incident light can cause specular resonance;
- the two or more first light scatterers and the two or more second light scatterers are disposed so as to be in contact with each other;
- and
- at least one selected from the two or more first light scatterers and the two or more second light scatterers has a shape other than a sphere, or both the two or more first light scatterers and the two or more second light scatterers are spheres but are disposed so as to form a structure other than a close-packed structure.
4 more elements
Dependencies are inferred from the claim text.