Lens, lens array and optical receiver
View Patent ↗In one embodiment, a lens has an object surface and an image surface, with the shape of the image surface being defined by an equation having a conic component and a cone component. The lens may be incorporated into an optical receiver having a photodetector that is positioned to receive light emitted from the image surface of the lens. In some uses, the image surface of the lens mitigates return loss through the lens.
1. An optical receiver, comprising:
a lens comprising:
an object surface and an image surface, wherein the shape of the image surface is defined by an equation having a conic component and a cone component; and
a reflective surface, positioned between the object surface and the image surface, to redirect light received at the object surface toward the image surface;
a photodetector, positioned to receive light emitted from the image surface of the lens.
2. The optical receiver of claim 1 , further comprising a housing, the housing holding at least the lens, and the housing comprising features to position the photodetector and an optical fiber with respect to the lens.
3. The optical receiver of claim 2 , wherein the surfaces of the lens are optimized to mitigate return loss through the lens for the optical fiber, the light expected to be received via the optical fiber, and locations at which the housing positions the optical fiber and photodetector with respect to the lens.
4. The optical receiver of claim 1 , wherein the shape of the image surface of the lens is defined by the equation:
z
=
c
(
x
2
+
y
2
)
1
+
1
-
(
1
+
k
)
c
2
(
x
2
+
y
2
)
+
d
x
2
+
y
2
where z is a z-coordinate of the image surface, x and y are lateral coordinates of the image surface, k is a conic constant, c Is a reciprocal of a radius of curvature of the conic component, and d is a cone constant.
5. The optical receiver of claim 1 , wherein the shape of the object surface of the lens is convex.
6. The optical receiver of claim 1 , wherein a diameter of a clear aperture of the image surface is smaller than a diameter of the object surface.
7. The optical receiver of claim 1 , wherein the lens further comprises a reflective surface, positioned between the object surface and the image surface, to redirect light received at the object surface toward the image surface.
8. The optical receiver of claim 1 , wherein the reflective surface of the lens is oriented to redirect light by approximately 90 degrees.
9. The optical receiver of claim 1 , wherein the surfaces of the lens are molded into a composite polymer material.
10. The optical receiver of claim 9 , wherein the polymer material comprises a polyetherimide.
11. The optical receiver of claim 1 , further comprising:
at least one additional lens, wherein all of the lenses have similarly configured object and image surfaces, and wherein all of the lenses are molded into a common structure; and
at least one additional photodetector, wherein each photodetector is similarly positioned with respect to a corresponding one of the lenses.
12. A lens comprising an object surface and an image surface, wherein the shape of the image surface is defined by an equation having a conic component and a cone component, and wherein the shape of the image surface is defined by the equation:
z
=
c
(
x
2
+
y
2
)
1
+
1
-
(
1
+
k
)
c
2
(
x
2
+
y
2
)
+
d
x
2
+
y
2
where z is a z-coordinate of the image surface, x and y are lateral coordinates of the image surface, k is a conic constant, c is a reciprocal of a radius of curvature of the conic component, and d is a cone constant.
13. The lens of claim 12 , wherein the shape of the object surface is convex.
14. The lens of claim 12 , wherein a diameter of a clear aperture of the image surface is smaller than a diameter of the object surface.
15. The lens of claim 12 , further comprising a reflective surface, positioned between the object surface and the image surface, to redirect light received at the object surface toward the image surface.
16. The lens of claim 12 , wherein the reflective surface is oriented to redirect light by approximately 90 degrees.
17. The lens of claim 12 , wherein the surfaces of the lens are molded into a polymer material.
18. The lens of claim 17 , wherein the polymer material comprises a polyetherimide.