Phase masks for use in holographic data storage
First Claim
1. A write head for a holographic data storage system, the write head comprising:
- a spatial light modulator that is arranged into an array of pixels that can each separately modulate light that is directed toward the spatial light modulator; and
a phase mask that is capable of varying the phase of light passing therethrough, the magnitude of the phase variation being dependent on the particular portion of the phase mask that the light passes through;
wherein the phase mask is provided on an interior surface of the spatial light modulator.
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Accused Products
Abstract
A spatial light modulator (SLM) having a phase mask that is provided as an internal component thereof. The phase mask can be provided as a multilevel surface of relatively higher index of refraction material on an inner surface of a transmissive cover window or as a separate transmissive window between the cover window and the pixels of the SLM. If the phase mask is to be used with a liquid crystal SLM, then it may be desirable to planarize the surface of the cover window contacting the liquid crystal by providing a layer of relatively lower index of refraction material adjacent the multilevel surface. The phase mask can also be provided on the transmissive cover window by patterned ion deposition, exposing patterned light to a photopolymeric material, or in some other suitable fashion. Arranging for the pixel electrodes to be at one of multiple levels rather than lying in an exactly planar relationship can also effectively create the phase mask.
38 Citations
22 Claims
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1. A write head for a holographic data storage system, the write head comprising:
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a spatial light modulator that is arranged into an array of pixels that can each separately modulate light that is directed toward the spatial light modulator; and
a phase mask that is capable of varying the phase of light passing therethrough, the magnitude of the phase variation being dependent on the particular portion of the phase mask that the light passes through;
wherein the phase mask is provided on an interior surface of the spatial light modulator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A write head for a holographic data storage system, the write head comprising:
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a spatial light modulator that is arranged into an array of pixels that can each separately modulate light that is directed toward the spatial light modulator;
a glass window located on one side of the spatial light modulator in close proximity to the array of pixels of the spatial light modulator; and
a phase mask that is capable of varying the phase of light passing therethrough, the magnitude of the phase variation being dependent on the particular portion of the phase mask that the light passes through;
wherein the phase mask is located between the glass window and the array of pixels of the spatial light modulator. - View Dependent Claims (18)
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19. A write head for a holographic data storage system, the write head comprising:
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a spatial light modulator that is arranged into an array of pixels that can each separately modulate light that is directed toward the spatial light modulator; and
a phase mask that is capable of varying the phase of light passing therethrough, the magnitude of the phase variation being dependent on the particular portion of the phase mask that the light passes through;
wherein the phase mask is located within 200 μ
m of the pixels of the spatial light modulator.
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20. A write head for a holographic data storage system, the write head comprising:
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a spatial light modulator that is arranged into an array of pixels that can each separately modulate light that is directed toward the spatial light modulator, the pixels having a pitch of p; and
a phase mask that is capable of varying the phase of light passing therethrough, the magnitude of the phase variation being dependent on the particular portion of the phase mask that the light passes through;
wherein the phase mask is within a distance d of the pixels of the spatial light modulator, where d is equal to p2/λ
, where λ
is the wavelength of the light directed toward the spatial light modulator.
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21. A write head for a holographic data storage system, the holographic data storage system having an imaging system, the write head comprising:
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a spatial light modulator that is arranged into an array of pixels that can each separately modulate light that is directed toward the spatial light modulator; and
a phase mask that is capable of varying the phase of light passing therethrough, the magnitude of the phase variation being dependent on the particular portion of the phase mask that the light passes through;
wherein the phase mask is sufficiently close to the pixels of the spatial light modulator to allow the imaging system of the holographic data storage system to resolve both the phase mask and the pixels. - View Dependent Claims (22)
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Specification