Numerical analysis of photoinduced chirality in azobenzene polymer and its application as photoaddressable polarization altering elements

Optical performances of a unique photoinduced chiral material were investigated. The material employed in our study is an azobenzene-based copolymer (PCDY50) that exhibits a very large photoinduced birefringence and a superior stability of photoinduced molecular orientation state. The photoinduced chirality of the PCDY50 thin film was analyzed in detail by elliptical analysis on the basis of either circular or linear polarization. The validity of the processes is demonstrated by comparing experimental results and calculations. Consequently, the formulation based on circular polarization is appropriate for analyzing the relationship between the polarization state of incident and transmitting beams accurately. Furthermore, photoaddressable polarization-altering functions, for example, as an optical rotator, an ellipticity modificator and a circular polarization generator were examined by applying the invariant ellipticity (or azimuth) state condition to an 800-nm-thick PCDY50 film. Some possible applications of the photoinduced chiral thin film are also suggested.