Browse Prior Art Database

Holographic Memory with Rapid Access

IP.com Disclosure Number: IPCOM000077937D
Original Publication Date: 1972-Oct-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Pohl, DW: AUTHOR

Abstract

Digital data recorded in hologram form can be accessed rapidly, by reading out a complete page of information at one stroke in a kind of optical time-multiplex mode. The interrogating beam is directed into a stack of equidistantly spaced translucent phase hologram plates. Accessing means comprise a laser light source, controllable beam deflector, and a unidirectional beam splitter (with polarization-dependent-reflectivity and a quarter wave plate) to direct the backscattered read out beams laterally towards an array of photocells, which are connected via time-multiplex signal gates to a processor for interpretation of the output signals.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Holographic Memory with Rapid Access

Digital data recorded in hologram form can be accessed rapidly, by reading out a complete page of information at one stroke in a kind of optical time- multiplex mode. The interrogating beam is directed into a stack of equidistantly spaced translucent phase hologram plates. Accessing means comprise a laser light source, controllable beam deflector, and a unidirectional beam splitter (with polarization-dependent-reflectivity and a quarter wave plate) to direct the backscattered read out beams laterally towards an array of photocells, which are connected via time-multiplex signal gates to a processor for interpretation of the output signals.

A single interrogating laser pulse causes backscattering of a train of optical information pulses from each consecutive hologram plate. These answer pulses appear staggered in time and will be gated and handled with electrical means. Thus (with unaltered i.e. fixed position of the beam deflector) a complete page of information can be read out at one stroke.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]