Thermally reversible and reorganizable crosslinking polymers for volume bragg gratings
AssigneeFacebook Technologies, LLC
InventorsAustin LANE, Matthew E. COLBURN
Life of this patent
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Abstract
The disclosure provides thermally reversible and reorganizable polymers for volume Bragg gratings. These polymers can be used in any volume Bragg gratings materials, but they are particularly useful in 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. The reorganizable polymers are part of the matrix, and when heat is applied, specific crosslinked bonds break up allowing the material to relax, and permitting more monomers for the second writing step to enter the matrix. When heat is removed, crosslinking bonds re-form but with different, reorganized, bonding partners.
Claims20
A resin mixture comprising a first polymer precursor comprising a blocked isocyanate group of Formula I:
- and a second polymer precursor comprising a polymerizable or crosslinkable group,
- wherein X is a group selected from CRa, NRa, O, and S, and Ra is independently selected from hydrogen, optionally substituted alkyl, and optionally substituted alkenyl.
A method of recording a volume Bragg grating on a recording material comprising a resin mixture comprising a first polymer precursor comprising an isocyanate component and an isocyanate blocking component, and a second polymer precursor comprising a polymerizable or crosslinkable group the method comprising:
- reacting the isocyanate component with the isocyanate blocking component to form a first polymer precursor comprising a blocked isocyanate group of Formula I:
- wherein X is a group selected from CRa, NRa, O, and S, and Ra is independently selected from hydrogen, optionally substituted alkyl, and optionally substituted alkenyl;
- partially or completely polymerizing or crosslinking the second polymer precursor to form a volume Bragg grating;
- and
- raising the temperature of the recording material to unblock the isocyanate, wherein the temperature is raised before or after polymerizing or crosslinking the second polymer precursor to form the volume Bragg grating.
Dependencies are inferred from the claim text.