Optical element and system using the same
View Patent ↗An optical element may include a first diffractive structure having a radially symmetric amplitude function and a second diffractive structure having a phase function. The second diffractive structure may serve as a vortex lens. A system employing the optical element may include a light source and/or a detector.
1. A vortex lens, comprising a diffractive surface defined by a surface function having a radially symmetric phase function and an angularly symmetric phase function, the surface function being selectively adjustable to control launch conditions and manage reflections, wherein the angularly symmetric phase function is given by
m
arctan
(
y
x
)
,
where m is a mode number indicating a speed with which a phase of the angularly symmetric phase function is changing.
2. The vortex lens as claimed in claim 1 , wherein the radially symmetric phase function is a lens function.
3. The vortex lens as claimed in claim 2 , wherein the lens function is given by
π
(
x
2
+
y
2
)
λ
f
,
where f is the focal length of the lens function and λ is a wavelength of the light source.
4. The vortex lens as claimed in claim 1 , wherein m equals 3.
5. The vortex lens as claimed in claim 1 , wherein the radially symmetric phase function is a polynomial.
6. The vortex lens as claimed in claim 5 , wherein the polynomial is a polynomial expansion.
7. An optical system configured to transfer light from a light source to an optical fiber, the optical system comprising a diffractive surface defined by a surface function having a radially symmetric phase function and an angularly symmetric phase function, the surface function being selectively adjustable to control launch conditions and manage reflections, wherein the angularly symmetric phase function is given by
m
arctan
(
y
x
)
,
where m is a mode number indicating a speed with which a phase of the angularly symmetric phase function is changing.
8. The optical system as claimed in claim 7 , wherein the radially symmetric phase function is a lens function.
9. The optical system as, claimed in claim 8 , wherein the lens function is given by
π
(
x
2
+
y
2
)
λ
f
,
where f is the focal length of the lens function and λ is a wavelength of the light source.
10. The optical system as claimed in claim 7 , wherein m equals 3.
11. The device as claimed in claim 7 , wherein the radially symmetric phase function is a polynomial.
12. The device as claimed in claim 11 , wherein the polynomial is a polynomial expansion.
13. A vortex lens, comprising a diffractive surface defined by a surface function having a radially symmetric phase function and an angularly symmetric phase function, the surface function being selectively adjustable to control launch conditions and manage reflections, wherein the radially symmetric phase function is a lens function given by
π
(
x
2
+
y
2
)
λ
f
,
where f is the focal length of the lens function and λ is a wavelength of the light source.
14. An optical system configured to transfer light from a light source to an optical fiber, the optical system comprising a diffractive surface defined by a surface function having a radially symmetric phase function and an angularly symmetric phase function, the surface function being selectively adjustable to control launch conditions and manage reflections, wherein the radially symmetric phase function is a lens function given by
π
(
x
2
+
y
2
)
λ
f
,
where f is the focal length of the lens function and λ is a wavelength of the light source.