Optical data storage medium with multiple writable data layers separated by dieletric layers

Claim 2

An optical data storage medium having multiple data recording layers for use in a laser-based optical data storage system, the medium comprising: a first light transmissive member having a first surface that supports a first one on the multiple data recording layers and an opposite surface that forms an outer face of the medium and from which laser radiation enters the medium; a first writable data recording layer overlying the first surface of the first light transmissive member for receipt of focused laser light transmitted through the first light transmissive member; a dielectric layer overlying the first writable data recording layer; a light transmissive medium overlying the dielectric layer; a second writable data recording layer overlying the light transmissive medium for receipt of focused laser light transmitted through the first light transmissive member and the light transmissive medium, the light transmissive medium spacing the second writable data layer from the first writable data layer, whereby when the laser light is focused on the second writable data layer it is not focused on the first writable data layer; and a protective medium overlying the second writable data recording layer.

Claim 3

The medium of claim 1, wherein the first and second writable data recording layers are comprised of a phase change material.

Claim 4

The medium of claim 2, wherein the phase change material is comprised of materials that lie substantially along the tieline connecting GeTe and Sb 2 Te 3 .

Claim 5

The medium of claim 2, wherein the phase change material is GeTe.

Claim 6

The medium of claim 2, wherein the phase change material is Sb 2 Te 3 .

Claim 7

The medium of claim 2, wherein the phase change material is Te 52 .5 Ge 15 .3 Sb 33 .

Claim 8

The medium of claim 2, wherein the phase change material is Ge 2 Sb 2 Te 5 .

Claim 9

The medium of claim 2, wherein the phase change material is GeSb 2 Te 4 .

Claim 10

The medium of claim 2, wherein the phase change material is GeSb 4 Te 7 .

Claim 11

The medium of claim 2, wherein the first and second phase change layers have a thickness between 20 and 800 Angstroms.

Claim 12

The medium of claim 1, wherein the first and second writable data recording layers are WORM layers.

Claim 13

The medium of claim 11, wherein the WORM layers are comprised of a tellurium-selenium alloy.

Claim 14

The medium of claim 11, whrein the WORM layers are 20-800 Angstroms thick.

Claim 15

The medium of claim 1, wherein the first and second writable data recording layers are comprised of a magneto-optical material.

Claim 16

The medium of claim 14, wherein the magneto-optical material is a rare earth transition metal.

Claim 17

The medium of claim 14, wherein the magneto-optical layers are 20-800 Angstroms thick.

Claim 18

The medium of claim 1, wherein the light transmissive medium is 100-300 microns thick.

Claim 19

The medium of claim 1, wherein the light transmissive medium is a solid transparent member.

Claim 20

The medium of claim 1, wherein the light transmissive medium is an optical cement.

Claim 21

The medium of claim 1, wherein the dielectric layer is comprised of ZrO 2 .

Claim 22

The medium of claim 1, wherein the dielectric layer is comprised of ZnS.

Claim 23

The medium of claim 1, wherein the dielectric layer is comprised of SiNx.

Claim 24

The medium of claim 1, wherein the dielectric layer is comprised of mixed oxides.

Claim 25

The medium of claim 1, further comprising a second dielectric layer located between the light transmissive medium and the second writable data recording layer.

Claim 26

An optical data storage medium having multiple data recording surfaces for use in a laser-based optical data storage system, the medium comprising: a first light transmissive member having a first surface that supports a first one on the multiple data recording surfaces and an opposite surface that forms an outer face of the medium and from which laser radiation enters the medium; a first writable data storage surface overlying the first surface of the light transmissive member for receipt of focused laser light transmitted through the first light transmissive member; an antireflection dielectric layer overlying the first data surface; a light transmissive medium overlying the antireflection dielectric layer; a second writable data storage surface overlying the light transmissive medium for receipt of focused laser light transmitted through the first light transmissive member and the light transmissive medium, the light transmissive medium spacing the second writable data surface from the first writable data surface, whereby when the laser light is focused on the second writable data surface it is not focused on the first writable data surface; and a protective medium overlying the second data surface.

Claim 27

An optical data storage medium having multiple data recording surfaces for use in a laser-based optical data storage system, the medium comprising: a first light transmissive member having a first surface that supports a first one on the multiple data recording surfaces and an opposite surface that forms an outer face of the medium and from which laser radiation enters the medium; a first writable data storage surface overlying the first surface of the light transmissive member for receipt of focused laser light transmitted through the first light transmissive member; an antireflection dielectric layer overlying the first data surface; a light transmissive medium overlying the antireflection dielectric layer; a second writable data storage surface overlying the light transmissive medium for receipt of focused laser light transmitted through the first light transmissive member and the light transmissive medium, the light transmissive medium spacing the second writable data surface from the first writable data surface, whereby when the laser light is focused on the second writable data surface it is not focused on the first writable data surface; and a protective medium overlying the second data surface.

Claim 28

The medium of claim 25, wherein the first and second writable data recording layers are comprised of a phase change material.

Claim 29

The medium of claim 26, wherein the phase change material is comprised of materials that lie along the tieline connecting GeTe and Sb 2 Te 3 .

Claim 30

The medium of claim 26, wherein the phase change material is GeTe.

Claim 31

The medium of claim 26, wherein the phase change material is Sb 2 Te 3 .

Claim 32

The medium of claim 26, wherein the phase change material is Te 52 .5 Ge 15 .3 Sb 33 .

Claim 33

The medium of claim 26, wherein the phase change material is Ge 2 Sb 2 Te 5 .

Claim 34

The medium of claim 26, wherein the phase change material is GeSb 2 Te 4 .

Claim 35

The medium of claim 26, wherein the phase change material is GeSb 4 Te 7 .

Claim 36

The medium of claim 26, wherein the first and second phase change layers have a thickness between 20 and 800 Angstroms.

Claim 37

The medium of claim 25, wherein the first and second writable data recording layers are WORM layers.

Claim 38

The medium of claim 35, wherein the WORM layers are comprised of a tellurium-selenium alloy.

Claim 39

The medium of claim 35, wherein the WORM layers are 20-800 Angstroms thick.

Claim 40

The medium of claim 25, wherein the first and second writable data recording layers are comprised of a magneto-optical material.

Claim 41

The medium of claim 38, whrein the magneto-optical material is a rare earth transition metal.

Claim 42

The medium of claim 38, wherein the magneto-optical layers are 20-800 Angstroms thick.

Claim 43

The medium of claim 25, wherein the light transmissive medium is 100-300 microns thick.

Claim 44

The medium of claim 25, wherein the light transmissive medium is a solid transparent member.

Claim 45

The medium of claim 25, wherein the light transmissive medium is an optical cement.

Claim 46

The medium of claim 25, wherein the antireflection dielectric layer is comprised of MnF.

Claim 47

The medium of claim 25, further comprising a second dielectric layer located between the light transmissive medium and the second data surface.

Claim 48

The medium of claim 45, wherein the second dielectric layer is comprised of ZrO 2 .

Claim 49

The medium of claim 45, wherein the second dielectric layer is comprised of ZnS.

Claim 50

The medium of claim 45, wherein the second dielectric layer is comprised of SiNx.

Claim 51

The medium of claim 45, wherein the second dielectric layer is comprised of mixed oxides.