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Hologram Generating Apparatus

IP.com Disclosure Number: IPCOM000091359D
Original Publication Date: 1968-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Habegger, MA: AUTHOR [+3]

Abstract

Total internal reflection is employed in this apparatus for making a hologram. High resolution and contrast of the image and a large angular view of the object are obtained using this method. Birefringent plate 1 is immersed in Arochlors* oil 2. The latter has an index of refraction approximately equal to the index of refraction of plate 1 which can take the form of sodium nitrate. Optic axis 4 of plate 1 is parallel to the surface of such plate. These surfaces are polished. Photographic emulsion 3 is proximately positioned beneath the plate 1.

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Hologram Generating Apparatus

Total internal reflection is employed in this apparatus for making a hologram. High resolution and contrast of the image and a large angular view of the object are obtained using this method. Birefringent plate 1 is immersed in Arochlors* oil
2. The latter has an index of refraction approximately equal to the index of refraction of plate 1 which can take the form of sodium nitrate. Optic axis 4 of plate 1 is parallel to the surface of such plate. These surfaces are polished. Photographic emulsion 3 is proximately positioned beneath the plate 1.

In the recording process, light beam 5 is incident on plate 1. The polarization component perpendicular to optic axis 4 passes through plate 1 to emulsion 3 as the reference beam. The polarization component of beam 5 parallel to optic axis 4 sees the extraordinary index of refraction of plate 1 and is totally reflected. This is because the angle of incidence of beam 5 is larger than the critical angle of plate 1. This totally reflected light is incident on object 6 after passing through quarter-wave plate 7.

The light striking object 6 is reflected back through quarter-wave plate 7. The reflected, linearly polarized light is oriented by plate 7 in the same polarization direction as reference beam 5. Any orthogonal components are totally reflected at incident angles greater than the critical angle. The optimum light ratio between the reference beam and the diffused light reflected from the obje...