Abstract:

Studies of the electrooptic effect in potassium tantalate niobate (KTN) and Li doped KTN in the vicinity of the ferroelectric phase transition are reported. It was observed that in KTN the standard electrooptic behavior is accompanied by electrically induced depolarization of the light traversing through the crystal. This behavior is attributed to the influence of the fluctuating dipolar clusters that are formed in KTN above the ferroelectric phase transition due to the emergence of the Nb ions out of the center of inversion of the unit cell. It was shown in addition that this behavior is inhibited in Li doped KTN, which enables exploiting the large electrooptic effect in these crystals.