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Optically Controlled System for Bubble Domain Memories

IP.com Disclosure Number: IPCOM000080881D
Original Publication Date: 1974-Feb-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Kuhn, L: AUTHOR [+3]

Abstract

In contrast with current-controlled switches, a scanning laser beam is used to achieve random switching of bubble domains in a bubble domain system, such as a memory. The present optical technique provides very efficient use of the area of the bubble domain material.

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Optically Controlled System for Bubble Domain Memories

In contrast with current-controlled switches, a scanning laser beam is used to achieve random switching of bubble domains in a bubble domain system, such as a memory. The present optical technique provides very efficient use of the area of the bubble domain material.

Fig. 1 shows a plurality of logic gates, G, which are optically activated. These logic gates are made of materials such as FeRh which are placed near the entrance of the individual shift registers. This ordered alloy FeRh has an abrupt transition from an antiferromagnetic to ferromagnetic state, as its temperature is raised to a critical value near 330 degrees K. Thus, its properties can be altered by heating, as for instance by a laser beam.

During the read and write operations, the logic gates are opened selectively by shining a laser beam at the desired logic gate.

During storage operation, no light is applied to any gate which should remain closed. Since FeRh has a magnetic moment close to that of permalloy, the dimensions of the logic gate are similar to that of the conventional permalloy I-bar.

Fig. 2 shows another information processing scheme which can be achieved by placing logic gates G between registers. The signals on lines 1 and 3 can be sampled and combined on line 2, in order to perform certain types of transversal filtering.

In all envisioned configurations, a logic gate is turned on by localized heating by an incident laser beam,...