Holographic Polymer Dispersed Liquid Crystal (HPDLC) Transmission Gratings Formed by Visible Light Initiated Thiol-Ene Photopolymerization (Postprint)
Abstract
We report on the initial development of a visible initiator for thiol-ene photoplymerization using the 647 nm radiation from a Krypton ion laser. The photoinitiator system consists of the dye oxazine 170 perchlorate and the co-initiator benzoyl peroxide. Electron transfer occurs between the singlet excited state of the oxazine dye and benxoyl peroxide with subsequent decomposition of the peroxide yielding benzoyl oxy radicals capable of free radical initiation. We demonstrate that this photoinitiation system enables holographic patterning of HPDLC gratings as initial Bragg transmission gratings with a periodicity less than one micron using 647 nm radiation. These gratings were electrically switchable between a diffractive and transmissive state. Morphology studies using bright field transmission electron microscopy (BFTEM) indicate the phase sparation of nearly spherical shaped nematic liquid crystal droplets of several hundred nanometers in diameter. This demonstration suggests that reflection gratings can be written using this photoinitiator system and 647 nm radiation which have switchable notch wavelengths approaching 2 microns.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2006
- Accession Number
- ADA474687
Entities
People
- Jeremy M. Wofford
- Lalgudi V. Natarajan
- Pamela F. Lloyd
- Richard L. Sutherland
- Stephen A. Siwecki
- Timothy J. Bunning
- Vincent P. Tondiglia
Organizations
- Air Force Research Laboratory