CHARACTERISTIC FEATURES OF ULTRAVIOLET PHOTOREFRACTION IN IRON-DOPED ALPHA-LIIO3 AT LOW-TEMPERATURES

The temperature dependence of ultraviolet photorefraction of iron-dope d alpha-LiIO3 crystals is studied. Within the temperature range of 120 -220 K diffraction efficiency and two-wave mixing gain increase dramat ically with decreasing temperature and become as high as 36% and 3.1 c m(-1), respectively, below 120 K. The results of holographic recording experiments are compared with measurements of the dielectric suscepta nce, electric conductivity, and absorption of acoustic waves to establ ish a relationship between the change in photorefraction and the tempe rature dependence of the dielectric and ultrasonic behavior. Iron dopi ng of alpha-LiIO3 enhances the photorefraction considerably. [S0163-18 29(98)05615-X].