AbstractThe complex strain‐optical coefficient, complex stress‐optical coefficient, complex modulus of elasticity and the corresponding loss tangent of phase angles between the stress, strain and birefringence have been measured for several high polymers in the frequency range from 0.001 to 10 cycles/sec. Frequency and temperature dependences of the dynamic optical properties of vulcanized Hevea rubber are very similar to those of the dynamic mechanical properties. On the other hand, the dynamic optical properties of polyethylene and polypropylene show remarkable dispersions in the above frequency range. The dynamic optical behavior of these three materials are very typical and are quite different from each other. The differences have been explained by considering different frequency dependences of three kinds of deformation mechanism, namely, orientation of molecules in amorphous region, deformation of spherulites, and orientation of cryst