DIFFRACTIVE OPTICAL ELEMENT, OPTICAL SYSTEM AND OPTICAL APPARATUS
First Claim
1. A diffractive optical element, comprising:
- two diffraction gratings made of a first material and a second material, respectively, the two diffraction gratings each having a grating surface and being in contact with each other at the grating surfaces,wherein the first and second materials satisfy all of the following conditions, and the second material is a material obtained by mixing a resin material with a particulate material satisfying all of the following conditions;
nd1≧
1.48
ν
d1≧
40
(−
1.665E−
07×
ν
d13+5.213E−
05×
ν
d12−
5.656E−
03×
ν
d1+0.675) ≦
θ
g,F1≦
(−
1.665E−
07×
ν
d13+5.213E−
05×
ν
d12−
5.656E−
03×
ν
d1+0.825)
(−
1.687E−
07×
ν
d13+5.702E−
05×
ν
d12−
6.603E−
03×
ν
d1+1.40
0) ≦
θ
g,d1≦
(−
1.687E−
07×
ν
d13+5.702E−
05×
ν
d12−
6.603E−
03 ×
ν
d1+1.58
0)
nd2≦
1.6
ν
d2≦
30
θ
g,F2≦
(−
1.665E−
07×
ν
d23+5.213E−
05×
ν
d22−
5.656E−
03 ×
ν
d2+0.675)
θ
g,d2≦
(−
1.687E−
07×
ν
d23+5.702E−
05×
ν
d22−
6.603E−
03×
ν
d2+1.400)
nd1−
nd2>
0
ndb2≧
1.70
ν
db2≦
20where ng1, nF1, nd1, and nC1 are refractive indexes of the first material for g-line, F-line, d-line, and C-line, respectively,ng2, nF2, nd2, and nC2 are refractive indexes of the second material for g-line, F-line, d-line, and C-line, respectively, andnFb2, ndb2, and nCb2 are refractive indexes of the particulate material for F-line, d-line, and C-line, respectively, and
ν
d1=(nd1−
1)/(nF1−
nC1)
ν
d2=(nd2−
1)/(nF2−
nC2)
θ
g,F1=(ng1−
nF1)/(nF1−
nC1)
θ
g,d1=(ng1−
nd1)/(nF1−
nC1)
θ
g,F2=(ng2−
nF2)/(nF2−
nC2)
θ
g,d2=(ng2−
nd2)/(nF2−
nC2)
μ
db2=(ndb2−
1)/(nFb2−
nCb2).
1 Assignment
0 Petitions
Accused Products
Abstract
The diffractive optical element includes two diffraction gratings made of different materials and being in contact with each other at their grating surfaces. The materials satisfy the following conditions, and the second material is obtained by mixing a resin material with a particulate material satisfying the following conditions: nd1≧1.48, νd1≧40, (−1.665E−07×νd13+5.213E−05×νd12−5.656E×03×νd1+0.675)≦θg,F1≦(−1.665E−07×νd13+5.213E−05×νd12−5.656E−03×νd1+0.825), (−1.687E−07×νd13+5.702E−05×νd12−6.603E−03×νd1+1.400)≦θg,d 1≦(−1.687E−07×νd13+5.702E−05×νd12−6.603E−03×νd1+1.580), nd2≦1.6, νd2≦30, θg,F2≦(−1.665E−07×νd23+5.213E−05×νd22−5.656E−03×νd2+0.675 ), θg,d2≦(−1.687E−07×νd23+5.702E−05×νd22−6.603E−03×νd2+1.400 ), nd1-nd2≧0, ndb2≧1.70, νdb2≦20. The element achieves a high diffraction efficiency in a specific diffraction order over a wide wavelength range.
-
Citations
11 Claims
-
1. A diffractive optical element, comprising:
-
two diffraction gratings made of a first material and a second material, respectively, the two diffraction gratings each having a grating surface and being in contact with each other at the grating surfaces, wherein the first and second materials satisfy all of the following conditions, and the second material is a material obtained by mixing a resin material with a particulate material satisfying all of the following conditions;
nd1≧
1.48
ν
d1≧
40
(−
1.665E−
07×
ν
d13+5.213E−
05×
ν
d12−
5.656E−
03×
ν
d1+0.675) ≦
θ
g,F1≦
(−
1.665E−
07×
ν
d13+5.213E−
05×
ν
d12−
5.656E−
03×
ν
d1+0.825)
(−
1.687E−
07×
ν
d13+5.702E−
05×
ν
d12−
6.603E−
03×
ν
d1+1.40
0) ≦
θ
g,d1≦
(−
1.687E−
07×
ν
d13+5.702E−
05×
ν
d12−
6.603E−
03 ×
ν
d1+1.58
0)
nd2≦
1.6
ν
d2≦
30
θ
g,F2≦
(−
1.665E−
07×
ν
d23+5.213E−
05×
ν
d22−
5.656E−
03 ×
ν
d2+0.675)
θ
g,d2≦
(−
1.687E−
07×
ν
d23+5.702E−
05×
ν
d22−
6.603E−
03×
ν
d2+1.400)
nd1−
nd2>
0
ndb2≧
1.70
ν
db2≦
20where ng1, nF1, nd1, and nC1 are refractive indexes of the first material for g-line, F-line, d-line, and C-line, respectively, ng2, nF2, nd2, and nC2 are refractive indexes of the second material for g-line, F-line, d-line, and C-line, respectively, and nFb2, ndb2, and nCb2 are refractive indexes of the particulate material for F-line, d-line, and C-line, respectively, and
ν
d1=(nd1−
1)/(nF1−
nC1)
ν
d2=(nd2−
1)/(nF2−
nC2)
θ
g,F1=(ng1−
nF1)/(nF1−
nC1)
θ
g,d1=(ng1−
nd1)/(nF1−
nC1)
θ
g,F2=(ng2−
nF2)/(nF2−
nC2)
θ
g,d2=(ng2−
nd2)/(nF2−
nC2)
μ
db2=(ndb2−
1)/(nFb2−
nCb2). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification