Holographic memory having spherical recording medium

Claim 2

In a holographic memory having a memory medium with a plurality of locations at which holograms may be stored and having an object and a reference beam for forming holograms at each of the plurality of locations on the memory medium, and wherein the object and reference beams are directed along object and reference beam channels, respectively, the improvement comprising: a memory medium having a curved surface proximate a portion of a sphere, the sphere having a diameter along the optical axis of the object beam channel; and reference beam pivoting means for pivoting the reference beam about a reference beam pivot point proximate the sphere.

Claim 3

The invention of claim 1 and further comprising: object beam pivoting means for pivoting the object beam about an object beam pivot point.

Claim 4

The invention of claim 2 wherein the holographic memory includes page composer means positioned in the path of the object beam proximate the object beam pivot point.

Claim 5

The invention of claim 2 wherein the object beam pivot point is proximate the sphere.

Claim 6

The invention of claim 3 and further comprising: page composer means positioned in the object beam channel proximate the object beam pivot point for creating a bit pattern in the object beam; and Fourier transform lens means positioned in the object beam channel proximate the page composer means for performing a Fourier transform of the bit pattern produced by the page composer means.

Claim 7

The invention of claim 2 wherein the object beam pivoting means comprises first lens means.

Claim 8

The invention of claim 1 wherein the reference beam pivoting means comprises second lens means.

Claim 9

The invention of claim 7 wherein the second lens means includes a lens array.

Claim 10

A holographic memory comprising: light source means for providing a light beam; beam splitter means for splitting the light beam into a reference beam and an object beam; beam directing means for simultaneously directing the object beam along an object beam channel and the reference beam along a reference beam channel to coincide at selected locations during the writing stage of operation; memory medium means for the storage of a plurality of holograms at different locations of the memory medium means, the memory medium means having a surface proximate a portion of a sphere, the sphere having a center proximate the optical axis of the object beam channel; page composer means positioned in the object beam channel for creating a bit pattern in the object beam during the writing stage; and reference beam pivoting means for pivoting the reference beam about a reference beam pivot point, the reference beam pivot point being positioned proximate the intersection of the reference beam channel and the sphere.

Claim 11

A holographic memory comprising: light source means for providing a light beam; beam splitter means for splitting the light beam into a reference beam and an object beam; beam directing means for simultaneously directing the object beam along an object beam channel and the reference beam along a reference beam channel to coincide at selected locations during the writing stage of operation; memory medium means for the storage of a plurality of holograms at different locations of the memory medium means, the memory medium means having a surface proximate a portion of a sphere, the sphere having a center proximate the optical axis of the object beam channel; page composer means positioned in the object beam channel for creating a bit pattern in the object beam during the writing stage; and reference beam pivoting means for pivoting the reference beam about a reference beam pivot point, the reference beam pivot point being positioned proximate the intersection of the reference beam channel and the sphere.

Claim 12

The holographic memory of claim 9 and further comprising object beam pivoting means for pivoting the object beam at an object beam pivot point.

Claim 13

The holographic memory of claim 10 wherein the page composer is positioned proximate the object beam pivot point.

Claim 14

The holographic memory of claim 11 and further comprising Fourier transform lens means positioned in the object beam channel proximate the page composer means for performing a Fourier transform of the bit pattern produced by the page composer means.

Claim 15

The holographic memory of claim 10 wherein the object beam pivot point is positioned proximate the intersection of the object beam channel and the sphere.

Claim 16

The holographic memory of claim 9 wherein the beam directing means comprises: light beam deflector means for deflecting the object and reference beam to a plurality of resolvable positions.

Claim 17

The holographic memory of claim 14 wherein the reference beam pivoting means comprises lens means.

Claim 18

The holographic memory of claim 15 wherein the lens means comprises: a first array of individual lenses positioned in the reference beam channel, each lens of the array being positioned at one of the plurality of resolvable positions for reducing the beam diameter of the resolvable positions; and field lens means for pivoting the reference beam at the reference beam pivoting point.

Claim 19

The holographic memory of claim 16 wherein the lens means further comprises: collimating lens means positioned proximate the reference beam pivot point for collimating the reference beam.