Abstract A method of storing, reading and erasing information in an alkali halide crystal containing F centers and having semitransparent electrical layers on opposite surfaces. Binary information is stored or erased by alternately applying a high D.C. electric field across the crystal while simultaneously illuminating a small area of the crystal with F light. Light exposure of the crystal area with a field and without a field may be equated to writing (or erasing and rewriting) the binary digits zero and one, respectively. Reading the stored information is similar except that the D.C. field is switched on electronically after sensing the digit zero so as to erase any absorption produced by the reading light. This system is entirely fatigue-free and is operable at a single temperature while using one laser beam, instead of two, for writing, erasing and reading in an effectively nondestructive manner.
In a method of sequentially storing and erasing information in a thin alkali halide crystal containing F centers maintained at temperatures below which F'' center formation occurs and having semi-transparent, electrically conducting layers on opposite surfaces thereof for application of a D.C. electric field comprising: selectively exposing a first part of said crystal with F band light, said part representing a first bit of stored information; and, selectively exposing a second part of said crystal with F band light while simultaneously applying a D.C. electric field across opposite surfaces of said crystal to cause the formation of F'' centers representing a second bit of stored information.
Claim 2
Dependent Claim
106 words
In a method of sequentially storing and erasing information in a thin alkali halide crystal containing F centers maintained at temperatures below which F'' center formation occurs and having semi-transparent, electrically conducting layers on opposite surfaces thereof for application of a D.C. electric field comprising: selectively exposing a first part of said crystal with F band light, said part representing a first bit of stored information; and, selectively exposing a second part of said crystal with F band light while simultaneously applying a D.C. electric field across opposite surfaces of said crystal to cause the formation of F'' centers representing a second bit of stored information.
Claim 3
Dependent Claim
45 words
A method as in claim 1 including the step of reading stored information by interrogating said selected parts with F band light to determine the presence of F centers and including the switching on of said D.C. electric field when interrogating said second crystal part.
Claim 4
Dependent Claim
12 words
A method as in claim 1 wherein said crystal comprises potassium chloride.