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High-Speed Character/Pattern Generator

IP.com Disclosure Number: IPCOM000042024D
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Bjorklund, GC: AUTHOR [+2]

Abstract

A high speed character/pattern generator has a character mask that is made of a photochemical holeburning (PCHB) material, such as color centers in an alkali halide host, in which each character is stored at a different frequency within the zero-phonon line. A particular example would be R2 centers in LiF. All of the characters are stored in the same volume, superimposed with the same optical system, except at different frequencies. Retrieval of an individual character is accomplished by selecting the appropriate frequency and illuminating the medium. Since all characters co-exist in the same volume, the "reconstructed" position is invariant with character selection. Character selection can be rapid by using either current-tuned GaAs laser diodes or electro-optically tuned dye lasers.

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High-Speed Character/Pattern Generator

A high speed character/pattern generator has a character mask that is made of a photochemical holeburning (PCHB) material, such as color centers in an alkali halide host, in which each character is stored at a different frequency within the zero-phonon line. A particular example would be R2 centers in LiF. All of the characters are stored in the same volume, superimposed with the same optical system, except at different frequencies. Retrieval of an individual character is accomplished by selecting the appropriate frequency and illuminating the medium. Since all characters co-exist in the same volume, the "reconstructed" position is invariant with character selection. Character selection can be rapid by using either current-tuned GaAs laser diodes or electro-optically tuned dye lasers. Frequency tuning in the microsecond time scale is within the current state of the art. Since the frequency width of a photochemical hole is typically 1000 times less than the width of the zero phonon line, up to 1000 characters or patterns can be stored and retrieved from a single device. The drawing shows the recording of the character set into the PCHB medium 10 using a tunable laser 12, beam-forming optics 14, relay optics 16 and mask set 18. With each different frequency, the appropriate mask 20 is interposed into the beam 22 and that character recorded in terms of a spatial variation of the depth of the photochemical hole burned at that fr...