Compensation for the birefrigence of an optical polymer by the anisotropic molecule dopant method and design of the anisotropic molecule dopant

Birefringence induced by the orientation of polymer main chains during an injection-molding or extrusion processing degrades the performance of optical devices that require maintaining the polarization state of incident light. We have compensated for the birefringence of optical polymers by the anisotropic molecule dopant method. The anisotropic molecule dopant method has problems that thermal degradation and the bleedout of an anisotropic molecule in an injection molding. In this study, we designed biphenyl-3,4,3',4'-tetracarboxylic acid tetramethyl ester (BPTM) as an anisotropic molecule for an application to an injection molding. The birefringence of the injection molded poly(methylmethacrylate)(PMMA) samples doped with 7 wt% of BPTM was reduced by about 90% compared to the PMMA sample.