Zero-birefringence optical polymers

Here we demonstrate, for the first time, that it is possible to synthesize a polymer that exhibits no orientational birefringence and no photoelastic birefringence using two methods. In these methods, the contributions of monomers and an anisotropic dopant to orientational birefringence and photoelastic birefringence are analyzed experimentally, after which the composition of a ternary copolymer or a binary copolymer including the dopant is adjusted, based on the results, to compensate for both types of birefringence. By the methods and fine adjustment of the composition, we synthesized poly(methyl methacrylate (MMA)/2,2,2-trifluoroethyl methacrylate (3FMA)/benzyl methacrylate = 52.0/42.0/6.0(w/w/w)) and poly(MMA/3FMA = 85.0/15.0(w/w)) containing 2.8 wt % of trans-stilbene that exhibited close to zero birefringence.