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US 7,072,275 B2Granted
Optical single-bit recording and fluorescent readout utilizing aluminum oxide single crystals
AssigneeLandauer, Inc.
InventorsMark Akselrod, Sergei Orlov
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Abstract
The present invention provides methods and apparatuses for writing information to, reading information from, and erasing information on a luminescent data storage medium comprising Al2O3. The method includes writing and erasing of the information using photoionization via sequential two-photon absorption and non-destructive reading the information using fluorescent detection. The apparatuses for writing and reading the information incorporate confocal detection and spherical aberration correction for multilayer volumetric fluorescent data storage. The methods also allow multilevel recording and readout of information for increased storage capacity.
Claims75
A method of writing information to a data storage medium comprising the steps of:
- providing a luminescent data storage medium comprising Al2O3;
- and
- writing said information to said luminescent data storage medium with an optical source, wherein said information is written to said luminescent data storage medium by using a two-photon absorption technique and a photo-ionization technique resulting in removal of an electron from a color center in said luminescent data storage medium and moving said electron to a thermally stable trap in said luminescent data storage medium.
A method of writing information to a data storage medium comprising the steps of:
- providing a luminescent data storage medium comprising Al2O3;
- and
- writing said information to said luminescent data storage medium with an optical source, wherein said luminescent data storage medium comprises:
- a base material comprising Al2O3;
- a first dopant comprising Mg;
- and
- a second dopant comprising carbon, wherein said luminescent data storage medium includes a plurality of at least one type of oxygen vacancy defect.
4 more elements
A method of reading information stored on a data storage medium comprising the steps of:
- (a) exciting a luminescent data storage medium with an optical source to thereby cause said luminescent data storage medium to emit a fluorescent light signal, wherein said luminescent data storage medium comprises Al2O3 and wherein said optical source emits a read laser beam having a wavelength in the range of an absorption band of said luminescent data storage medium;
- and
- (b) measuring said laser induced fluorescence light signal from said luminescent data storage medium, to thereby read said information stored on said luminescent data storage medium, wherein step (a) comprises exciting said luminescent data storage medium using a one-photon absorption technique without causing photo-ionization of the storage centers to thereby cause said luminescent data storage medium to emit a fluorescent light signal and thereby read said luminescent data storage medium non-destructively.
A method of reading information stored on a data storage medium comprising the steps of:
- (a) exciting a luminescent data storage medium with an optical source to thereby cause said luminescent data storage medium to emit a fluorescent light signal, wherein said luminescent data storage medium comprises Al2O3 and wherein said optical source emits a read laser beam having a wavelength in the range of an absorption band of said luminescent data storage medium;
- and
- (b) measuring said laser induced fluorescence light signal from said luminescent data storage medium, to thereby read said information stored on said luminescent data storage medium, wherein step (a) comprises exciting said luminescent data storage medium using a simultaneous two-photon absorption technique without causing photo-ionization of the storage centers to thereby cause said luminescent data storage medium to emit a fluorescent light signal and thereby read said luminescent data storage medium non-destructively.
A method of reading information stored on a data storage medium comprising the steps of:
- (a) exciting a luminescent data storage medium with an optical source to thereby cause said luminescent data storage medium to emit a fluorescent light signal, wherein said luminescent data storage medium comprises Al2O3 and wherein said optical source emits a read laser beam having a wavelength in the range of an absorption band of said luminescent data storage medium;
- and
- (b) measuring said laser induced fluorescence light signal from said luminescent data storage medium, to thereby read said information stored on said luminescent data storage medium, wherein said luminescent data storage medium comprises:
- a base material comprising Al2O3;
- a first dopant comprising magnesium;
- and
- a second dopant comprising carbon, wherein said luminescent data storage medium includes a plurality of at least one type of oxygen vacancy defect.
4 more elements
A method of erasing information stored on a data storage medium comprising the steps of:
- (a) providing a luminescent data storage medium comprising Al2O3, said luminescent data storage medium having said information stored thereon;
- and
- (b) illuminating said luminescent data storage medium with an optical source to thereby erase said information.
An apparatus comprising:
- a luminescent data storage medium comprising Al2O3;
- and
- an optical source for writing information to said luminescent data storage medium, wherein said information is written to said luminescent data storage medium by using a two-photon absorption technique and a photo-ionization technique resulting in removal of an electron from a color center in said luminescent data storage medium and moving said electron to a thermally stable trap in said luminescent data storage medium.
An apparatus comprising:
- a luminescent data storage medium comprising Al2O3;
- an optical source for reading information by exciting said luminescent data storage medium to thereby cause said luminescent data storage medium to emit a fluorescent light signal when information is stored on said luminescent data storage medium;
- and
- measuring means for detecting said emitted fluorescent light signal, wherein said information is written to said luminescent data storage medium by using a two-photon absorption technique and a photo-ionization technique resulting in removal of an electron from a color center in said luminescent data storage medium and moving said electron to a thermally stable trap in said luminescent data storage medium.
1 more element
An apparatus comprising:
- a luminescent data storage medium comprising Al2O3;
- an optical source for reading information by exciting said luminescent data storage medium to thereby cause said luminescent data storage medium to emit a fluorescent light signal when information is stored on said luminescent data storage medium;
- measuring means for detecting emitted fluorescent light signal;
- and
- a second optical source for writing information to said luminescent data storage medium.
2 more elements
An apparatus comprising:
- a luminescent data storage medium comprising Al2O3;
- an optical source for writing information to said luminescent data storage medium;
- and,
- compensation means for adaptive spherical aberration compensation of said optical source to allow optical addressing with a diffraction limited light spot at a depth of at least 10 microns.
1 more element
An apparatus comprising:
- a luminescent data storage medium comprising Al2O3;
- and
- writing means for writing information to said luminescent data storage medium by using a two-photon absorption technique and a photo-ionization technique resulting in removal of an electron from a color center in said luminescent data storage medium and moving said electron to a thermally stable trap in said luminescent data storage medium, said writing means comprising a first optical source.
An apparatus comprising:
- a luminescent data storage medium comprising Al2O3;
- and
- an optical source for writing information to said luminescent data storage medium, wherein said luminescent data storage medium comprises:
- a base material comprising Al2O3;
- a first dopant comprising Mg;
- and
- a second dopant comprising carbon, wherein said luminescent data storage medium includes a plurality of at least one type of oxygen vacancy defect.
4 more elements
An apparatus comprising:
- a luminescent data storage medium comprising Al2O3;
- an optical source for reading information by exciting said luminescent data storage medium to thereby cause said luminescent data storage medium to emit a fluorescent light signal when information is stored on said luminescent data storage medium;
- and
- measuring means for measuring said emitted fluorescent light signal, wherein said luminescent data storage medium comprises:
- a base material comprising Al2O3;
- a first dopant comprising Mg;
- and
- a second dopant comprising carbon, wherein said luminescent data storage medium includes a plurality of at least one type of oxygen vacancy defect.
5 more elements
Dependencies are inferred from the claim text.