Multiple holographic lens

Claim 1

A method of fabricating a multiple holographic lens comprising the steps of: fabricating an off-axis fly's eye lens with a plurality of non-overlapping lenslets, each such lenslet having a predetermined f-number and covering a non-negligible area on the lens; inserting the fly's eye lens in a first beam of light from a coherent source to provide a plurality of refracted beams in one to one correspondence with the lenslets of the fly's eye lens; positioning a holographic recording medium so that an area thereon is illuminated simultaneously by each of the refracted beams; directing a second beam of light from the coherent source toward the area of the holographic recording medium illuminated by the refracted beams; exposiing the holographic recording medium simultaneously to the second beam and the refracted beams; developing the holographic recording medium to form the multiple holographic lens therefrom.

Claim 2

A method of fabricating a multiple holographic lens comprising the steps of: fabricating an off-axis fly's eye lens with a plurality of non-overlapping lenslets, each such lenslet having a predetermined f-number and covering a non-negligible area on the lens; inserting the fly's eye lens in a first beam of light from a coherent source to provide a plurality of refracted beams in one to one correspondence with the lenslets of the fly's eye lens; positioning a holographic recording medium so that an area thereon is illuminated simultaneously by each of the refracted beams; directing a second beam of light from the coherent source toward the area of the holographic recording medium illuminated by the refracted beams; exposiing the holographic recording medium simultaneously to the second beam and the refracted beams; developing the holographic recording medium to form the multiple holographic lens therefrom.

Claim 5

A method of fabricating a multiple holographic lens comprising the steps of: determining a desired number, pattern, spacing and off-axis angle of a plurality of focal points in a focal plane of the multiple holographic lens; positioning a first holographic recording medium directly behind a mask opaque to radiation from a coherent light source, said mask having an opening of predetermined shape and size, said opening allowing radiation from the coherent light source to pass through; directing a first beam from the coherent light source toward the opening in the mask; directing a second beam from the coherent source through a spatial filter, then through a lens and then toward the opening in the mask such that an angle between the first and second beams determines the desired off-axis angle of the focal points of the multiple holographic lens; indexing the first holographic recording medium so that an unexposed area thereon registers with the opening in the mask, said area being one of a plurality of non-overlapping areas equal in number to the desired number of focal points of the multiple holographic lens, said plurality of areas being located on a plane of the first holographic recording medium in an identical pattern to the desired pattern of focal points on the focal plane of the multiple holographic lens; exposing the area on the first holographic recording medium behind the opening in the mask simultaneously to the first and second beams; repeating the indexing and exposing steps until all the areas on the first holographic recording medium are exposed; developing the first holographic recording medium; inserting the first holographic recording medium in a third beam from the coherent light source, said third beam being identical to the first beam; so that the third beam provides a plurality of refracted beams in one to one correspondence with the exposed areas of the first holographic recording medium; positioning a second holographic recording medium so that an area thereon is simultaneously illuminated by each of the refracted beams; directing a fourth beam from the coherent light source toward the area on the second holographic recording medium illuminated by the refracted beams; exposing the second holographic recording medium simultaneously to the fourth beam and the refracted beams; developing the second holographic recording medium to form the multiple holographic lens therefrom.

Claim 6

A method of fabricating a multiple holographic lens comprising the steps of: determining a desired number, pattern, spacing and off-axis angle of a plurality of focal points in a focal plane of the multiple holographic lens; positioning a first holographic recording medium directly behind a mask opaque to radiation from a coherent light source, said mask having an opening of predetermined shape and size, said opening allowing radiation from the coherent light source to pass through; directing a first beam from the coherent light source toward the opening in the mask; directing a second beam from the coherent source through a spatial filter, then through a lens and then toward the opening in the mask such that an angle between the first and second beams determines the desired off-axis angle of the focal points of the multiple holographic lens; indexing the first holographic recording medium so that an unexposed area thereon registers with the opening in the mask, said area being one of a plurality of non-overlapping areas equal in number to the desired number of focal points of the multiple holographic lens, said plurality of areas being located on a plane of the first holographic recording medium in an identical pattern to the desired pattern of focal points on the focal plane of the multiple holographic lens; exposing the area on the first holographic recording medium behind the opening in the mask simultaneously to the first and second beams; repeating the indexing and exposing steps until all the areas on the first holographic recording medium are exposed; developing the first holographic recording medium; inserting the first holographic recording medium in a third beam from the coherent light source, said third beam being identical to the first beam; so that the third beam provides a plurality of refracted beams in one to one correspondence with the exposed areas of the first holographic recording medium; positioning a second holographic recording medium so that an area thereon is simultaneously illuminated by each of the refracted beams; directing a fourth beam from the coherent light source toward the area on the second holographic recording medium illuminated by the refracted beams; exposing the second holographic recording medium simultaneously to the fourth beam and the refracted beams; developing the second holographic recording medium to form the multiple holographic lens therefrom.