Birefringence and second harmonic generation in PVDF/PMMA blends

The poling dynamics and relaxation process in PVDF/PMMA blends are studied with the second harmonic generation (SHG) and birefringence measurements in order to determine the temporal stabilities and temperature dependences. T he Maker fringe and the phase modulation methods were used for studying the SHG and optical birefringence measurements, respectively. Both the birefri ngence and the SHG intensity increase during the poling process in the same fashion. The relaxation process of the sample whose polar order increases with poling is studied with the SHG at several poling temperatures. Both th e poling and the relaxation processes exhibit a form of the stretched expon ential behavior with different characteristic times.