Electro-optical study of polymer stabilized cholesteric liquid crystals

POLY 526

Eric R. Beckel, eric.beckel@wpafb.af.mil1, Lalgudi V. Natarajan, Lalgudi.Natarajan@wpafb.af.mil2, Vincent P. Tondiglia, vincent.tondiglia@wpafb.af.mil2, Jeremy M. Wofford1, Richard L. Sutherland, richard.sutherland@wpafb.af.mil2, and Timothy J. Bunning, timothy.bunning@wpafb.af.mil1. (1) Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433, (2) Science Applications International Corporation, 4031 Col. Glenn Way, Dayton, OH 45431
Cholesteric liquid crystals (CLCs) have attracted significant attention for uses in photonic and electro-optic devices, such as photonic crystals, light shutters, light switches, and display applications. These materials selectively reflect circularly polarized light due to the existence of a macroscopic helical structure, where the reflected light is on the order of the helical pitch of the LC. To enhance the applications stated above, it is desired to selectively tune and subsequently remove this reflection notch from these devices. To mitigate the lifetime of an intermediate highly scattering focal conic state that exists between the reorientation from the clear to the reflective conformation, polymer stabilization can be introduced into the CLC. This polymer stabilization acts as an elastic memory for the rapid reorientation back into the cholesteric state. In this research, we examine the effect of holographically patterning the polymer stabilization to study the effect on the reflective and clear states of the device. These studies include the use of LCs with both positive and negative dielectric anisotropy. CLCs with negative dielectric anisotropy show further potential for tunable reflective notch devices.

Organic Thin Films for Photonic Applications
6:00 PM-8:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster

8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Polymer Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006