Optical multilayer

摘要

Disclosed is an optical multilayer comprising a polymeric substrate having a non-zero out-of plane birefringence and an amorphous polymeric overlayer that comprises an amorphous polymer having a Tg value above 160° C. and having the sign of its out-of-plane birefringence opposite to that of the polymeric substrate so as to provide a total out-of-plane phase retardation of said optical multilayer of between -30 nm and 30 nm for wavelengths of light between 400 and 700 nm.