Films for optical use and methods of making such films
View Patent ↗Films for optical use, articles containing such films, methods for making such films, and systems that utilize such films, are disclosed.
1. An optical system, comprising:
a lens for imaging light from an object to an image plane;
an optical filter comprising a plurality of layers positioned relative to the lens to reduce an amount of focused light of a wavelength λ by about 20 percent or more at the image plane relative to an identical optical system without the optical filter; and
a detector positioned at the image plane,
wherein one of the layers is disposed on a first surface of the lens and the optical filter is disposed on a surface of the detector.
2. The optical system of claim 1 , wherein the first surface has a radius of curvature of about two meters or less.
3. The optical system of claim 1 , wherein the image plane is about 5 cm or less from the lens.
4. The optical system of claim 1 , wherein the image plane is about 1 cm or less from the lens.
5. The optical system of claim 1 , wherein the image plane is about 0.5 cm or less from the lens.
6. The optical system of claim 1 , wherein the detector is a charge coupled device array or complementary metal oxide semiconductor array.
7. The optical system of claim 1 , wherein the plurality of layers comprise a plurality of dielectric layers.
8. The optical system of claim 1 , wherein alternating layers of the plurality of layers have different refractive indices.
9. The optical system of claim 1 , wherein the plurality of layers comprises a layer disposed on a second surface of the lens opposite the first surface.
10. The optical system of claim 1 , wherein λ is about 650 nm or more.
11. The optical system of claim 1 , wherein λ is between about 650 nm and 1,100 nm.
12. The optical system of claim 1 , wherein the optical filter reduces focused light of wavelength λ by about 50 percent or more at the image plane.
13. The optical system of claim 1 , wherein the optical filter reduces focused light of wavelength λ by about 80 percent or more at the image plane.
14. The optical system of claim 1 , wherein the optical filter reduces focused light of wavelength λ by about 90 percent or more at the image plane.
15. The optical system of claim 1 , wherein the optical filter reduces focused light of wavelength λ by about 95 percent or more at the image plane.
16. The optical system of claim 1 , further comprising a second lens for imaging light from the object to the image plane, wherein the one of the layers of the optical filter is disposed on a surface of the second lens.
17. The optical system of claim 1 , wherein rays of imaged light have a maximum divergence of about 20 degrees or less at the first surface.
18. The optical system of claim 1 , wherein rays of imaged light have a maximum divergence of about 15 degrees or less at the first surface.
19. The optical system of claim 1 , wherein rays of imaged light have a maximum divergence of about 10 degrees or less at the first surface.
20. The optical system of claim 1 , wherein the optical filter is positioned between the lens and the image plane.
21. A digital camera comprising the optical system of claim 1 .
22. A cell phone comprising the digital camera of claim 21 .