Optical volume memory

Details Optical volume memory Optical volume memory

1993-12-16

1995-12-05

Ryan, Patrick J.

Stock material or miscellaneous articles

Circular sheet or circular blank

Recording medium or carrier

428913, 430270, 430495, 430945, 346137, 346 761, B32B 300

Patent

active

054727596

ABSTRACT:
An optical memory material includes a two-photon storage component which can be written from a first to a second state in response to WRITE light, mixed with a signal component which fluoresces by one-photon absorption only at the written locations in response to READ light. The storage material may be a fulgide. The memory material may also include a frequency upconversion material to aid writing. Writing is performed by a spatial light modulator (SLM) with a dynamic focussing system, for concentrating sufficient power at WRITE locations for nonlinear two-photon absorption. Crosstalk is avoided during simultaneous writing in some embodiments, by spacing the individual WRITE beams apart by an integer number of inter-beam spacings, so that non-adjacent datels are written simultaneously in a "paragraph," and the non-written areas are written at a different time with different paragraphs. The memory material may be translated relative to the SLM to access different paragraphs, or accessed by an electronically sparsed SLM. Reading uses a sheet of READ light traversing the pages of written material to cause the signal component to fluoresce, and imaging the fluorescent pattern onto a detector array. The memory material may be stacked in layers, spaced apart by light waveguides, for guiding the READ beam to the page to be read. In another embodiment, writing and erasure are performed by a modulated quasi-one-dimensional sheet of light, intersecting a second, unmodulated sheet of light at a column within the memory material.

REFERENCES:
patent: 4052706 (1977-10-01), Spitz et al.
patent: 4288862 (1981-09-01), Ohhinata et al.
patent: 4333165 (1982-06-01), Swainson et al.
patent: 4927180 (1990-05-01), Trundle
patent: 5130058 (1992-07-01), Tanaka
patent: 5192644 (1993-03-01), Ohta
patent: 5246758 (1993-09-01), Matsui
patent: 5268862 (1993-12-01), Rentzepis
patent: 5296607 (1994-03-01), Tomoda
"Two-Photon Absorption Allows Data Storage in 3D", Bains, published at pp. 1-2 of OE Reports, vol. 118, published by Society of Photo-Optical Instrumentation Engineers Oct. 1993.
"Two Photon Three Dimensional Memory Hierarchy" by S. Eisner et al, presented at the Jul. 1992 SPIE meeting in San Diego.
"Photochromics of the Future", H. G. Heller, Electronic Materials from Silicon to Organics, 1991, edited by L. S. Miller et al, published by Plenum Publishing Corp.
"Potentials of Two-Photon Based 3D Optical Memories for High Performance Computing", May 10, 1990 by Hunter et al, published at pp. 2058-2066 of Applied Optics, vol. 29, No. 14.
"Three-Dimensional Optical Storage Memory", by D. A. Parthenopoulos et al., published at pp. 843-845 of the Aug. 25, 1989 issue of OE reports, published by SPIE, the International Society for Optical Engineering.
"Applications of Photochromic Polymer Films," by A. E. J. Wilson, published at pp. 232-238 of vol. 15, 1984 issue of Phys. Technol., printed in Northern Ireland.

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