Photorefractive recording mechanism of acoustic waves in crystals

Now some recording mechanisms of acoustic waves in crystals are known. Photorefractive mechanism, mechanism, connected with nonstationary photoconductivity under impulse radiation of the crystal and also mechanisms connected with nonlinear material equations [1-3] belong to them. Our experiments on recording of acoustic waves with the frequency of about 100 MHz under the radiation of LiNbO3 crystal with subnanosecond light impulses showed that in this case photorefractive mechanism of recording is the main one. On this condition the electrical fields of the recorded grid gets the value like that of electric field of acoustic wave in piezocrystal. As the value of the field is so high one must take into consideration the selfdifraction of the waves while examing the recording process [4]. In this work the recording kinetics of the acoustic waves in photorefractive crystals under the radiation by the ultrashort light impulses with repetition frequency equal to that of sound is considered.