High-Voltage Poling of a Bulk Sample of Disperse Red 1 Polymethylmethacrylate Guest-Host Polymer for U.S. Army Electro-optical Applications

Abstract : Much attention has been paid in recent years to poling thin-film doped polymers for electro-optics applications, mostly in the area of telecommunications switching devices. However, there are applications where a larger thickness of guest-host polymer results in enhanced performance of the electro-optic device, such as in terahertz (THz) generation. The thicker path length available in bulk poled polymers will allow for improved THz power, sensitivity and signal-to-noise ratio in both THz generators and detectors. Large area Pockels cells constructed from electro-optic (EO) guest-host polymers have uses as high speed modulators and shutters, and any application requiring a large d33 or r33 will potentially benefit from bulk-poled guest-host polymer systems. For large-aperture applications, the optical path length is longer and both poling and operating fields must still be transverse to the direction of light propagation which presents a tremendous challenge in building devices. Given the limitations of thin-film poling for fabricating large-aperture devices, the fabrication of a thick EO polymer slab with the proper orientation is an important goal. Our proposed solution is to pole a thick slab, cut, polish and re-orient 90 degrees. As a first step towards testing our proposed solution, we describe for the first time the fabrication and poling of a 700 micrometer thick bulk piece of polymethylmethacrylate (PMMA) doped with various concentrations of Disperse Red 1 (DR1). Maker fringe analysis will demonstrate that under the poling fields currently available to us (57 V/micrometer to 71 V/micrometer), that substantial ordering of the DR1 chromophores is occurring, resulting in birefringence and significant d33 and r33 values.