Diffraction grating element, production method of diffraction grating element, and method of designing diffraction grating element
AssigneeSumitomo Electric Industries, Ltd.
InventorsManabu Shiozaki, Masakazu Shigehara
Life of this patent
Estimating the term…
Abstract
In a diffraction grating element 10, between a first medium 11 and a fourth medium 14, a second medium 12 and a third medium 13 are disposed alternately to form a diffraction grating. The light, which enters the diffraction grating from the first medium 11, is diffracted at the diffraction grating portion and output to a fourth medium 14. Or, the light, which enters the diffraction grating from the fourth medium 14, is diffracted at the diffraction grating portion and output to the first medium 11. The index of refraction n1-n4 of each medium satisfies a relational expression of “n3<n1<n2, n3≦n4≦n2” or “n3≦n1≦n2, n3<n4<n2”.
Claims62
A diffraction grating element, comprising:
- given a first plane and a second plane parallel with each other, a first medium (index of refraction n1) provided at the outer side than the first plane being in contact with the first plane,
- a second medium (index of refraction n2) and a third medium (index of refraction n3, n3<n2) disposed alternately in a predetermined direction parallel with the first plane between the first plane and the second plane being in contact with the first plane and the second plane to constitute a diffraction grating, and
- a fourth medium (index of refraction n4) provided at the outer side than the second plane being in contact with the second plane, wherein
- each of the indexes of refraction n1-n4 of the first medium, the second medium, the third medium and the fourth medium satisfies a relational expression of “n3<n1<n2, n3≦n4≦n2”, or “n3≦n1≦n2, n3<n4<n2”, and
- both of the second medium and the third medium are solid.
A diffraction grating element, comprising:
- given a first plane and a second plane parallel with each other, a first medium (index of refraction n1) provided at the outer side than the first plane being in contact with the first plane,
- a second medium (index of refraction n2) and a third medium (index of refraction n3, n3<n2) disposed alternately in a predetermined direction parallel with the first plane between the first plane and the second plane being in contact with the first plane and the second plane to constitute a diffraction grating, and
- a fourth medium (index of refraction n4) provided at the outer side than the second plane being in contact with the second plane, wherein
- each of the indexes of refraction n1-n4 of the first medium, the second medium, the third medium and the fourth medium satisfies a relational expression of “n3<n1<n2, n3≦n4≦n2”, or “n3≦nl≦n2, n3<n4<n2”, and
- the first medium or the fourth medium is made of an isotropic material.
30-46. (canceled)
A diffraction grating element, comprising:
- given first-third planes disposed parallel with each other in order, a first medium (index of refraction ni) provided at the outer side than the first plane being in contact with the first plane,
- a second medium (index of refraction n2) and a third medium (index of refraction n3, n3<n2) disposed alternately in a predetermined direction parallel with the first plane between the second plane and the third plane being in contact with the second plane and the third plane to constitute a diffraction grating,
- a fourth medium (index of refraction n4) provided at the outer side than the third plane being in contact with the third plane, and
- a fifth medium (average index of refraction n5) provided between the first plane and the second plane being in contact with the first plane and the second plane, wherein
- given that the average index of refraction between the second plane and the third plane is nav, the average index of refraction n5 of the fifth medium satisfies a relational expression of “n1<n5<nav” or “nav<n5<n1”.
A diffraction grating element, comprising:
- a base plate,
- a first reflection-inhibiting portion provided on the base plate,
- a diffraction grating portion provided on the first reflection-inhibiting portion, and
- a second reflection-inhibiting portion provided on the diffraction grating portion, wherein
- the second reflection-inhibiting portion is in contact with a first medium,
- in the diffraction grating portion, a second medium and a third medium are disposed alternately in a predetermined direction parallel with the base plate to constitute a diffraction grating,
- in a waveband of 1.26 μm-1.675 μm, a wavelength of which reflectance is 10% or less is present.
A method of producing a diffraction grating element, the method comprising the steps of:
- forming a layer made of a predetermined material of which index of refraction changes by an irradiation of energy beam;
- and
- irradiating an energy beam onto the layer with a spatial strength modulation pattern to form a diffraction grating in which the second medium and the third medium with an index of refraction different from each other are disposed alternately in the layer.
A method of fabricating a diffraction grating element, the method comprising the steps of:
- forming a layer made of a predetermined material;
- and
- performing an etching on the layer with a predetermined spatial pattern to form a diffraction grating in which the second medium and the third medium with an index of refraction different from each other are disposed alternately in the layer.
A designing method of a diffraction grating element having a diffraction grating portion of which index of refraction changes periodically in a predetermined direction and a reflection-inhibiting portion on at least one of the top and the bottom of the diffraction grating portion, comprising the steps of:
- determining so that each of the diffraction grating portion and the reflection-inhibiting portion is formed with a film having an average index of refraction due to the media included therein and setting the phase change of light at the diffraction grating portion to 90°, and deriving refraction distribution of the diffraction grating element so that the reflectance is 10% or less at a desired wavelength.
Dependencies are inferred from the claim text.