Methods and apparatus for making holograms

A method for making a composite transmission hologram of a data set, the data set comprising about 100 two-dimensional, spaced apart data slices together representative of a three-dimensional physical system, comprising the steps of:

• providing a thin, substantially planar, photosensitive substrate having a first surface;
• determining a photosensitive exposure characteristic of said substrate;
• applying a reference beam characterized by a first wavelength to a substantially planar single substrate at a first incident angle with respect to said first surface, said single substrate comprising a photosensitive emulsion overlaying a thin film support;
• applying an object beam, characterized by said first wavelength, to said single substrate at a second incident angle substantially orthogonally thereto;
• consecutively interposing said plurality of data slices into said object beam to thereby record respective holograms within said emulsion corresponding to said data slices, while maintaining said first and said second angle constant;
• controlling, in accordance with said predetermined photosensitive exposure characteristics of said substrate, the effective exposure energy of each of said data slices during said recording step such that each of said recorded holograms are substantially equally bright;
• photochemically processing said single substrate to generate said composite hologram;
• applying a replay beam, characterized by said first wavelength, to said composite hologram at said first incident angle to thereby replay said composite hologram while maintaining a constant angular relationship between said replay beam and said single substrate, such that each of said holograms corresponding to said data slices exhibit substantially the same diffraction efficiency when simultaneously viewed, resulting in a bright, diffuse composite hologram suitable for detailed visual analysis.