Photoinduced birefringence and photoinduced optical rotation has been investigated on poly{4-[2-(methacryloyloxy)ethyloxy-4'-cyanoazobenzene]-co-4-[[2-(methacryloyloxy)ethyloxy]-2-methyl-4-(phenylazo)]azobenzene} (PCDY50). Originating in a good optical response of cyanoazobenzene side-chain and large birefringence of long pi-conjugated side chains, a fairly large photoinduced birefringence (0.28) and photoinduced optical rotation (41 degrees/mu m) could be observed. Some applications utilizing these superior photoresponsive properties of PCDY50 have been suggested and demonstrated.