Photopolymer media with enhanced dynamic range
View Patent ↗Dynamic range enhancing dopants for photopolymeric media are described. Also described are optical articles using these dopants and methods for making such optical articles.
1. A holographic storage medium comprising:
a support matrix;
a photoactive monomer;
a photoinitiator;
a dynamic range enhancing dopant (DRED) including a radical trap group and an immobilizing group, wherein;
the DRED is present in an amount of less than 0.72 wt %;
the radical trap group is capable of covalently attaching to a growing polymer chain formed from the photoactive monomer;
the immobilizing group is covalently attached to the support matrix; and
the holographic storage medium has an M/# per 200 μm medium at least 1.5 times the value of the same holographic storage medium without the DRED.
2. The holographic storage medium of claim 1 , wherein the holographic storage medium has a dynamic range that is 2 times or more the value of the dynamic range of the same holographic storage medium without the DRED.
3. The holographic storage medium of claim 1 , wherein the holographic storage medium has a dynamic range that is 3 times or more the value of the dynamic range of the same holographic storage medium without the DRED.
4. The holographic storage medium of claim 1 , wherein the holographic storage medium has a dynamic range that is 4 times or more the value of the dynamic range of the same holographic storage medium without the DRED.
5. The holographic storage medium of claim 1 , wherein the DRED comprises less than 0.23 wt % of the holographic storage medium.
6. The holographic storage medium of claim 1 , wherein the DRED comprises 0.02 wt % to 0.72 wt % of the holographic storage medium.
7. The holographic storage medium of claim 1 , wherein the radical trap group is selected from the group consisting of an alkenyl group, a nitro group, a nitrone group, and an aminoxyl group.
8. The holographic storage medium of claim 1 , wherein the alkenyl group is not sterically hindered.
9. The holographic storage medium of claim 8 , wherein the immobilizing group is selected from the group consisting of a hydroxyl group, an amine group, a carboxylic acid group, and an isocyanate group.
10. The holographic storage medium of claim 1 , wherein the radical trap group is a dithioester group.
11. The holographic storage medium of claim 1 , wherein the immobilizing group is selected from the group consisting of an hydroxyl group, an amine group, a carboxylic acid group, and an isocyanate group.
12. The holographic storage medium of claim 1 , further comprising in its composition an unbound polymerization retarder capable of diffusion.
13. The holographic storage medium of claim 1 , wherein the support matrix is a thermoset polyurethane.
14. The holographic storage medium of claim 1 , wherein the DRED includes an aminoxyl group.
15. A method of recording to a holographic storage medium comprising:
synthesizing the holographic storage medium, said synthesizing the holographic storage medium including:
synthesizing a support matrix, said synthesizing a support matrix including covalently attaching a DRED to the support matrix, wherein:
the DRED is present in an amount of less than 0.72 weight percent;
the DRED includes a radical trap group; and
the holographic storage medium has an M/# per 200 μm medium at least 1.3 times the value of the same holographic storage medium without the DRED;
recording holographic data in the holographic storage medium by polymerizing a photoactive monomer to create a growing polymer chain in the holographic storage medium; and
covalently attaching the growing polymer chain to the radical trap group.
16. The method of claim 15 , wherein said covalently attaching the growing polymer chain to the radical trap group occurs while recording data in the holographic storage medium.