Holographic recording techniques using reference zone of spatial light modulator
The invention is directed to holographic recording techniques that generate a data encoded object beam and a reference beam using a spatial light modulator of the holographic recording system. An input light source, e.g., comprising laser light conditioned by optical elements, can be used to illuminate the spatial light modulator. Different portions of the spatial light modulator are used to create the data encoded object beam and the reference beam, which are then made to interfere in a holographic medium to record a hologram.
1. A spatial light modulator comprising:
a first set of controllable optical elements to create a data encoded object beam from a perimeter portion of an input light beam; and
a second set of controllable optical elements to create a reference beam from an interior portion of the input light beam.
2. The spatial light modulator of claim 1 , wherein the second set of controllable optical elements are controlled to define a reference mask.
3. The spatial light modulator of claim 1 , wherein the second set of controllable optical elements optically adjusts one or more optical characteristics of the interior portion of the input light beam.
4. The spatial light modulator of claim 1 , wherein the second set of controllable optical elements optically adjusts a phase of the interior portion of the input light beam.
5. The spatial light modulator of claim 1 , wherein the second set of controllable optical elements optically adjusts a polarization of the interior portion of the input light beam.
6. The spatial light modulator of claim 1 , wherein the first and second sets of controllable optical elements include transmissive optical elements.
7. The spatial light modulator of claim 1 , wherein the first and second sets of controllable optical elements include reflective optical elements.
8. The spatial light modulator of claim 1 , further comprising a control unit to control the first and second sets of controllable optical elements.
9. A method comprising:
creating a data encoded object beam from a perimeter portion of an input light beam
using a first set of controllable optical elements of a spatial light modulator; and
creating a reference beam from an interior portion of the input light beam using a second set of controllable optical elements of the spatial light modulator.
10. A holographic data storage system comprising:
a holographic medium; and
a spatial light modulator including a first set of controllable optical elements to create a data encoded object beam from a perimeter portion of an input light beam, and a second set of controllable optical elements to create a reference beam from an interior portion of the input light beam, wherein the data encoded object beam and reference beam interfere in the holographic medium to create a hologram.
11. The system of claim 10 , wherein the second set of controllable optical elements are controlled to define a reference mask.
12. The system of claim 10 , wherein the second set of controllable optical elements optically adjusts one or more optical characteristics of the interior portion of the input light beam.
13. The system of claim 10 , wherein the second set of controllable optical elements optically adjusts a phase of the interior portion of the input light beam.
14. The system of claim 10 , wherein the second set of controllable optical elements optically adjusts a polarization of the interior portion of the input light beam.
15. The system of claim 10 , wherein the first and second sets of controllable optical elements include transmissive optical elements.
16. The system of claim 10 , wherein the first and second sets of controllable optical elements include reflective optical elements.
17. The system of claim 10 , further comprising a control unit to control the first and second sets of controllable optical elements.