William Karl Smothers

Photopolymers for holography

Photosensitive films composed of dye, initiator, acrylic monomers, and polymeric film-forming binder, and their use in recording volume phase transmission and reflection holograms are described. Systematic variation of monomer-binder combinations reveals that the maximum attainable index modulation (hologram efficiency) increases with increasing difference between the refractive indices of monomer and binder. Addition of plasticizer is also useful for increasing index modulation. Thermal and wet chemical processing methods for altering hologram properties are described.

Holographic notch filters

Holographic notch filters (HNF) are replacing dielectric filters in certain optical systems that incorporate single line laser sources. HNF characteristics, physical structure, specification, benefits, and customer acceptance are described for laser spectroscopy and laser surgery applications.

Hologram recording in du Pont's new photopolymer materials

New families of transmission and reflection holographic photopolymer materials and their performance are described. The materials are composed of polymeric binders, monomers, initiation system, and sensitizing dyes. The physical and holographic properties may be controlled by choice of components. Photopolymerization and diffusion of monomers is the proposed mechanism for recording of refractive index modulation. The materials are sensitized from the Uv to the red with typical exposure energies form 10 to 100 mJ/cm2. Hologram recording consists of exposure, UV cure, and heat processing. Significant refractive index modulation occurs during exposure. Processed holograms are insensitive to humidity and temperature. Holographic properties and performance of various formulations are discussed, as well as applications of these materials.

Color holography using DuPont holographic recording films

DuPont has developed holographic photopolymer films capable of producing high diffraction efficiency in full-color volume holograms and holographic optical elements. The properties of these films allows for a greater range of applications than has been considered feasible for color holograms. The recording mechanism and methods for holographic color recording in these materials is considered. Methods for full-color mastering and copying to achieve optimal performance in three-color recording are discussed. Examples of full-color holograms are presented.