Holographic apparatus for large field of view

Claim 2

A holographic apparatus for recording an aerodynamic phenomenon over a large portion of the surface of a cylinder, said apparatus comprising: a. means for generating a coherent beam of light; b. means for splitting said beam into a reference beam and a scene beam; c. a recording material extending over a substantial portion of the surface of a cylinder, said cylinder having a central axis, whereby the aerodynamic phenomenon along the central axis may be recorded; d. a first negative lens disposed in the path of said reference beam for projecting it onto said recording material, said negative lens providing a virtual source for said reference beam located substantially along said central axis; e. a first diffuser disposed in the path of said scene beam; f. a conical reflector disposed in the path of the diffused scene beam and for directing said scene beam onto said recording material substantially normal thereto, said conical reflector having an axis substantially coinciding with said central axis; g. a second negative lens for directing said scene beam onto said first diffuser; and h. means for making the path of said reference beam substantially equal to the path of said scene beam.

Claim 3

Holographic apparatus as defined in claim 1 wherein a second diffuser is disposed in the path of said scene beam following said conical reflector.

Claim 4

Holographic apparatus as defined in claim 1 wherein a quarter wave plate is disposed in the path of said coherent beam to create a reference and a scene beam, each being circularly polarized.

Claim 5

Holographic apparatus as defined in claim 1 wherein the ratio d/D is no more than 0.1, wherein D is the diameter of the cylinder forming said recording material, and wherein d is the diameter of the aerodynamic phenomenon to be recorded.

Claim 6

Holographic apparatus for recording an aerodynamic phenomenon in a wind tunnel or the like, said apparatus comprising: a. a recording material extending substantially over one half of the surface of a cylinder, said cylinder having a central axis; b. means for generating a coherent scene beam; c. a first diffuser of substantially annular shape disposed in the path of said scene beam and extending substantially at right angles to said recording material over substantially 180*; d. a conical reflector for reflecting said scene beam diffused by said first diffuser through a wind tunnel and substantially normal onto said recording material, said conical reflector having an axis substantially coinciding with said central axis; e. an optical element consisting of a previously recorded hologram extending adjacent to and substantially coextensive with said first diffuser, said hologram providing, when illuminated, a reference beam having a virtuAl source substantially along said central axis and arranged for illuminating said recording material; and f. means for generating a plurality of reference beams circumferentially spaced about said holographic elements for generating a light beam which is diffracted by said element onto said recording material.

Claim 7

Holographic apparatus for recording an aerodynamic phenomenon in a wind tunnel or the like, said apparatus comprising: a. a recording material extending substantially over one half of the surface of a cylinder, said cylinder having a central axis; b. means for generating a coherent scene beam; c. a first diffuser of substantially annular shape disposed in the path of said scene beam and extending substantially at right angles to said recording material over substantially 180*; d. a conical reflector for reflecting said scene beam diffused by said first diffuser through a wind tunnel and substantially normal onto said recording material, said conical reflector having an axis substantially coinciding with said central axis; e. an optical element consisting of a previously recorded hologram extending adjacent to and substantially coextensive with said first diffuser, said hologram providing, when illuminated, a reference beam having a virtuAl source substantially along said central axis and arranged for illuminating said recording material; and f. means for generating a plurality of reference beams circumferentially spaced about said holographic elements for generating a light beam which is diffracted by said element onto said recording material.

Claim 8

Holographic apparatus as defined in claim 5 wherein a separate optical holographic element is provided for each reference beam.

Claim 9

Holographic apparatus as defined in claim 6 wherein baffles are provided between adjacent reference beams to minimize interference therebetween.

Claim 10

Holographic apparatus as defined in claim 5 wherein a second diffuser is provided in the path of the diffused scene beam and following said conical reflector.

Claim 11

Apparatus for generating a holographic optical element which, when illuminated, will provide a reference beam having a virtual source in a central axis, said apparatus comprising: a. a portion of a wind tunnel; b. a recording material disposed about said wind tunnel over a large portion thereof and forming an annular surface substantially at right angles to said central axis, said recording material being adapted to be disposed near a second, semi-cylindrical recording material for recording a hologram of a phenomenon in the wind tunnel; c. means for generating a plurality of reference beams, each being coherent, said plurality of reference beams illuminating said recording material; and d. means including a lens disposed substantially along said central axis for generating a scene beam and for directing it onto said recording material, whereby the developed hologram will recreate said scene beam when illuminated by said plurality of reference beams to provide a reference beam illumination for the second recording material having a virtual point source substantially at the location of said lens.

Claim 12

Apparatus for generating a holographic optical element which, when illuminated, will provide a reference beam having a virtual source in a central axis, said apparatus comprising: a. a portion of a wind tunnel; b. a recording material disposed about said wind tunnel over a large portion thereof and forming an annular surface substantially at right angles to said central axis, said recording material being adapted to be disposed near a second, semi-cylindrical recording material for recording a hologram of a phenomenon in the wind tunnel; c. means for generating a plurality of reference beams, each being coherent, said plurality of reference beams illuminating said recording material; and d. means including a lens disposed substantially along said central axis for generating a scene beam and for directing it onto said recording material, whereby the developed hologram will recreate said scene beam when illuminated by said plurality of reference beams to provide a reference beam illumination for the second recording material having a virtual point source substantially at the location of said lens.