Retarder stack pairs for polarization basis vector transformations
A device for manipulating the polarization of light which includes a first retarder-stack (Stack 1 ) that converts the polarization of input light from a first polarization basis vector (PBV 1 ) to a second polarization basis vector (PBV 2 ), a second retarder-stack (Stack 2 ) that returns the polarization of light from PBV 2 to PBV 1 , and one or more optically functional layers between Stack 1 and Stack 2 . Stack 1 has a plurality of layers, wherein the number of layers, retardation values, and orientations of layers in Stack 1 are selected to produce a PBV 2 that is substantially spectrally-uniform over a prescribed range of wavelengths. PBV 1 is a non-trivial eigen-polarization of combined Stack 1 and Stack 2 . Stack 2 has a plurality of layers and Stack 2 is arranged in series with Stack 1 . Alternatively, instead of two different stacks, a reflector may be used to produce a return pass through Stack 1.
1. A device for manipulating a polarization of light, comprising:
a first retarder-stack (Stack 1 ) that converts a polarization of input light from a first polarization basis vector (PBV 1 ) to a second polarization basis vector (PBV 2 ), Stack 1 having a number of layers, retardation values, and orientations, wherein the number of layers, retardation values, and orientations of layers in Stack 1 are selected to produce a PBV 2 that is substantially spectrally-uniform over a prescribed range of wavelengths;
a second retarder-stack (Stack 2 ) that returns the polarization of light from PBV 2 to PBV 1 , wherein PBV 1 is a non-trivial eigen-polarization of combined Stack 1 and Stack 2 , Stack 2 having a plurality of layers, wherein Stack 2 is arranged in series with Stack 1 ; and
one or more optically functional layers between Stack 1 and Stack 2 ;
wherein each of Stack 1 and Stack 2 have base retarder layers and the base retarder layers of Stack 1 and Stack 2 each have a thickness direction retardation (R th ) that is greater than or equal to half of the in-plane pathlength difference (R e ) (R th ≥R e /2).
2. The device of claim 1 , wherein the layers of Stack 2 have a reverse-order (RO) arrangement with respect to the layers of Stack 1 .
3. The device of claim 1 , wherein each of Stack 1 and Stack 2 have base retarder layers and the base retarder layers of Stack 1 and Stack 2 each have a birefringence dispersion of near zero.
4. The device of claim 1 , wherein each of Stack 1 and Stack 2 have base retarder layers and the base retarder layers of Stack 1 and Stack 2 have reverse birefringence dispersion.
5. The device of claim 1 , wherein each of Stack 1 and Stack 2 have base retarder layers and the base retarder layers of Stack 1 and Stack 2 are one of cyclic-olefin polymer, cyclic olefin co-polymer, or polycarbonate.
6. The device of claim 1 , wherein the layers of Stack 1 and Stack 2 are solvent bonded to each other.
7. The device of claim 1 , wherein PBV 1 is a linear polarization and PBV 2 is the ±45°-rotated version of PBV 1 .
8. The device of claim 7 , wherein Stack 1 contains two or more half-wave retarders.
9. The device of claim 7 , wherein one or both of a positive c-plate and a crossed negative a-plate are inserted between Stack 1 and Stack 2 to reduce a composite R th of the device.
10. The device of claim 1 , wherein PBV 1 is a linear polarization and PBV 2 is a circular polarization.
11. The device of claim 10 , further including a first linear polarizer preceding Stack 1 and a second linear polarizer following Stack 2 , with the first and second linear polarizers having parallel or crossed absorption/reflection axes.
12. The device of claim 11 , wherein the first linear polarizer layer is clad with protective substrates having R th <5 nm.
13. The device of claim 10 , wherein PBV 2 has an ellipticity field-ratio that is at least 0.95 in red, green, and blue portions of a visible light spectrum.
14. The device of claim 10 , wherein PBV 2 has an ellipticity field-ratio that is at least 0.98 in red, green, and blue portions of a visible light spectrum.
15. The device of claim 10 , wherein the layers of Stack 2 have a reverse-order-reflection-about-zero (RORAZ) arrangement with respect to the layers of Stack 1 .
16. The device of claim 10 , wherein Stack 1 contains one or more half-wave retarders followed by a quarter-wave retarder.
17. The device of claim 16 , wherein Stack 1 contains M half-wave retarders with slow-axes oriented at angles (α 1 , α 2 . . . α M ) such that (α 2 >2α 1 , α 3 >2α 2 . . . ), producing a quasi-linear rotated SOP with orientation β=2(α M −α M-1 +α M-2 − . . . ), followed by a quarter-wave retarder with slow-axis orientation substantially along α 0 =(β+π/4).
18. The device of claim 15 , further including one or both of a positive c-plate and a crossed negative a-plate inserted between Stack 1 and Stack 2 to reduce a composite R th of the device.
19. A device for manipulating a polarization of light, comprising:
a first retarder-stack (Stack 1 ) that converts a polarization of input light from a first polarization basis vector (PBV 1 ) to a second polarization basis vector (PBV 2 ), Stack 1 having a number of layers, retardation values, and orientations, wherein the number of layers, retardation values, and orientations of layers in Stack 1 are selected to produce a PBV 2 that is substantially spectrally-uniform over a prescribed range of wavelengths;
a second retarder-stack (Stack 2 ) that returns the polarization of light from PBV 2 to PBV 1 , wherein PBV 1 is a non-trivial eigen-polarization of combined Stack 1 and Stack 2 , Stack 2 having a plurality of layers, wherein Stack 2 is arranged in series with Stack 1 ; and
one or more optically functional layers between Stack 1 and Stack 2 ;
wherein PBV 1 is a linear polarization and PBV 2 is the ±45°-rotated version of PBV 1 .
20. The device of claim 19 , wherein Stack 1 contains two or more half-wave retarders.
21. The device of claim 19 , wherein one or both of a positive c-plate and a crossed negative a-plate are inserted between Stack 1 and Stack 2 to reduce a composite R th of the device.
22. The device of claim 19 , wherein the layers of Stack 2 have a reverse-order (RO) arrangement with respect to the layers of Stack 1 .
23. A device for manipulating a polarization of light, comprising:
a first retarder-stack (Stack 1 ) that converts a polarization of input light from a first polarization basis vector (PBV 1 ) to a second polarization basis vector (PBV 2 ), Stack 1 having a plurality of layers having a number of layers, retardation values, and orientations, wherein the number of layers, retardation values, and orientations of layers in Stack 1 are selected to produce a PBV 2 that is substantially spectrally-uniform over a prescribed range of wavelengths;
a second retarder-stack (Stack 2 ) that returns the polarization of light from PBV 2 to PBV 1 , wherein PBV 1 is a non-trivial eigen-polarization of combined Stack 1 and Stack 2 , Stack 2 having a plurality of layers, wherein Stack 2 is arranged in series with Stack 1 ; and
one or more optically functional layers between Stack 1 and Stack 2 ;
wherein PBV 1 is a linear polarization and PBV 2 is a circular polarization.
24. The device of claim 23 , further including a first linear polarizer preceding Stack 1 and a second linear polarizer following Stack 2 , with the first and second linear polarizers having parallel or crossed absorption/reflection axes.
25. The device of claim 23 , wherein PBV 2 has an ellipticity field-ratio that is at least 0.95 in red, green, and blue portions of a visible light spectrum.
26. The device of claim 23 , wherein the layers of Stack 2 have a reverse-order-reflection-about-zero (RORAZ) arrangement with respect to the layers of Stack 1 .
27. The device of claim 23 , wherein Stack 1 contains one or more half-wave retarders followed by a quarter-wave retarder.
28. The device of claim 23 , wherein one or both of a positive c-plate and a crossed negative a-plate are inserted between Stack 1 and Stack 2 to reduce a composite R th of the device.