Total internal reflection aperture stop imaging
View Patent ↗In some example embodiments, there is provided an apparatus comprising a lens comprising a first medium having a first index of refraction and a second medium having a second index of refraction, wherein the first index of refraction is greater than the second index of refraction; wherein an interface between the first medium and the second medium is convex, and wherein total internal reflection from the first medium to the second medium forms an aperture on light transmission with edges dependent on the angle of light incidence. Related system, methods, and the like are also disclosed.
1. An apparatus comprising:
a lens comprising a first medium, a second medium, and a third medium, the first medium having a first index of refraction and the second medium having a second index of refraction,
wherein the first index of refraction is greater than the second index of refraction,
wherein an interface between the first medium and the second medium is convex, and
wherein the second medium is interposed between the first medium and the third medium to form an aperture providing, based at least on an angle of light incidence, a total internal reflection of at least some incident light passing from the first medium to the third medium.
2. The apparatus of claim 1 , wherein the convex interface between the first medium and the second medium is spherical.
3. The apparatus of claim 1 , wherein a plurality of surfaces within the lens are spherical and share a common center of curvature.
4. The apparatus of claim 1 , wherein the third medium is associated with a third index of refraction that is greater than the second index of refraction.
5. The apparatus of claim 1 , wherein a thickness of the second medium is less than the focal length of the apparatus.
6. A system comprising:
a plurality of lens layers each having a substantially spherical shape and each sharing a substantially common center of curvature, wherein the plurality of lens layers include a first layer, a second layer, and a third layer, wherein the first layer is associated with a first index of refraction and the second layer is associated with a second index of refraction, wherein the first index of refraction is greater than the second index of refraction, wherein an interface between the first layer and the second layer comprises a first convex internal surface, and wherein the second layer is interposed between the first layer and the third layer to form an aperture providing, based at least on an angle of light incidence, a total internal reflection of at least some incident light passing from the first layer to the third layer.
7. The system of claim 6 , wherein the third layer is associated with a third index of refraction that is higher than the second index of refraction, wherein an interface between the second layer and the third layer comprises a second convex internal surface, and wherein a separation between the first convex internal surface and the second convex internal surface is minimized to limit an angular deviation of light rays passing from the second layer to the third layer.