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Light Switch

IP.com Disclosure Number: IPCOM000098361D
Original Publication Date: 1960-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Ames, I: AUTHOR

Abstract

The light switch includes a switch element formed of a crystal of barium titanate 10 on which a pair of electrodes 11 is mounted. The element 10 is mounted between a pair of cross polarizers 12 and 13. One separates the light switch element from a light source 14. The other separates the light switch element from an output photomultiplier 15. A focus lens 16 precedes the polarizer 12. This switch operates at room temperature.

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Light Switch

The light switch includes a switch element formed of a crystal of barium titanate 10 on which a pair of electrodes 11 is mounted. The element 10 is mounted between a pair of cross polarizers 12 and 13. One separates the light switch element from a light source 14. The other separates the light switch element from an output photomultiplier 15. A focus lens 16 precedes the polarizer 12. This switch operates at room temperature.

The arrangement of the polarizers and the barium titanate crystal is such that the angle of acceptance 12A of polarizer 12 is parallel to the polar axis 10A of the barium titanate crystal. The angle of acceptance 13A of the polarizer 13 is rotated 90 degrees from it. As a result, in the absence of a signal applied to the electrodes 11, there is no change in the polarization of light passing through the crystal 10 and the entire light output is blocked by the polarizer 13. When a voltage signal, however, is applied between the electrodes 11, the polarization of light passing through the crystal is changed so that the entire light output of the crystal is not absorbed by the second polarizer 13.

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