Abstract: A method of and an apparatus for improving the selective positioning of single wall domains or bubble domains in a bubble domain memory system is disclosed. The method includes the use of slotted intersecting digit and word drive lines that form memory areas, each memory area being defined by the inside opposing edges of the slotted drive lines at each intersection. Each memory area has four quadrants, three of which are effectively optically blocked by an opaque shield--a bubble domain in the one unblocked quadrant provides the desired Faraday rotation of a plane polarized coherent light beam to generate a beamlet that is optically detected as a binary digital signal. The slotted drive lines are formed below the surface of the bubble domain supporting layer whereby the so-provided magneto static barriers prevent bubble domain sticking in a selected one quadrant of the four quadrants of the memory area and prevent bubble domain escape from the memory area itself.

Abstract: Defining the structuring of bubble domains in the magnetizable layer of a bubble domain memory plane is determined by modification of the magnetic characteristics of the magnetizable layer in the confinement area. The memory plane is comprised of a non-magnetic Gadolinium Gallium Garnet (GGG) layer which is a supporting substrate upon which is formed by the liquid phase epitaxy (LPE) method a magnetizable layer in which bubble domains are capable of being generated, sustained and moved about. Formed upon the bubble domain supporting magnetizable layer is a matrix array of conductive drive lines, the intersections of which define respective memory areas. In each memory area the position of the bubble domain in the magnetizable layer is determined by modifying the magnetic characteristics of the magnetizable layer in a confinement area as by an ion milling process. The ion milled confinement area along the line of the thickness gradient generates a perpendicular field H.sub.

Abstract: A light accessable transistor matrix (latrix) that utilizes an optical page composer having single wall domains, i.e., bubbles, in a layer of magnetizable material as the optical shutter or light valve is disclosed. The latrix is configured into an holographic memory system. The optical page composer is comprised of a magnetizable layer having orthogonal sets of D parallel digit lines and W parallel word lines, the DW intersections of which form DW memory areas. Each memory area has four quadrants defined by the intersecting digit line and word line. An opaque shield is oriented in each memory area for optically shielding a bubble except when in the exposed first quadrant within the memory area. Coincident current selection, e.g., concurrent half current selection, of one digit line and of one word line by half-select write signals permits the one fully selected memory area to be separately selected for the write operation.

Abstract: A method of improving the selective positioning of single wall domains or bubbles in a memory system is disclosed. The method includes the use of a predetermined stripline-magnetic layer separation and a drive current signal of a waveform having a relatively high initial amplitude and a relatively decreasing trailing amplitude.