Fluorene derivatized monomers and polymers for volume Bragg gratings
The disclosure provides recording materials include fluorene derivatized monomers and polymers for use in volume Bragg gratings, including, but not limited to, volume Bragg gratings for holography applications. Several fluorene structures are disclosed: simply substituted fluorenes, cardo-fluorenes, and spiro-fluorenes. Fluorene derivatized polymers in Bragg gratings applications lead to materials with higher refractive index, low birefringence, and high transparency. Fluorene derivatized monomers/polymers can be used in any volume Bragg gratings materials, including two-stage polymer materials where a matrix is cured in a first step, and then the volume Bragg grating is written by way of a second curing step of a monomer.
1. A recording material for writing a volume Bragg grating, the material comprising a transparent support, a polyurethane matrix, and a photopolymerizable imaging precursor compound of Formula II(b):
wherein in Formula II(b):
at least one of R 1 and R 2 comprises a group selected from
at least one of R 1 and R 2 comprises a polymerizable or crosslinkable group selected from optionally substituted alkenyl, optionally substituted cycloalkenyl, optionally substituted alkynyl, optionally substituted acrylate, optionally substituted methacrylate, optionally substituted styrene, optionally substituted epoxide, optionally substituted thiirane, optionally substituted glycidyl, optionally substituted lactone, optionally substituted lactam, and optionally substituted carbonate.
2. The recording material of claim 1 , wherein the material has a thickness of between 1 μm and 500 μm.
3. The recording material of claim 1 , wherein the at least one of R 1 and R 2 comprises a polymerizable or crosslinkable group selected from optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted epoxide, optionally substituted glycidyl, optionally substituted acrylate, and optionally substituted methacrylate.
4. The recording material of claim 1 , wherein the at least one of R 1 and R 2 comprises a polymerizable or crosslinkable group selected from optionally substituted alkenyl and optionally substituted alkynyl.
5. The recording material of claim 1 , wherein the at least one of R 1 and R 2 comprises a polymerizable or crosslinkable group selected from optionally substituted epoxide and optionally substituted glycidyl.
6. The recording material of claim 1 , wherein the at least one of R 1 and R 2 comprises a polymerizable or crosslinkable group selected from optionally substituted acrylate and optionally substituted methacrylate.
7. A volume Bragg grating recorded on the recording material of claim 1 , wherein the grating is characterized by a Q parameter equal to or greater than 5, wherein
Q
=
2
π
λ
0
d
n
0
Λ
2
and wherein λ 0 is a recording wavelength, d is the thickness of the recording material, n 0 is a refractive index of the recording material, and Λ is a grating constant.