In this research we measure some of the optical parameters of
Barium Titanate crystal (BaTiO3), such as signal beam gain, coupling
constant (exponential gain coefficient), change in index refraction and
photorefractive sensitivity, which are very significant for optical data
storage. In all experiment, two- wave mixing configuration at 632.8 nm (He-
Ne laser) were used. Experimental data for change in signal beam gain
versus input angle of two beam, beam intensity ratio, pump beam intensity
and grating vector, were plotted and compared with Kukhtarev theory. Using
of experimental data, we calculated other optical parameters such as
exponential gain coefficient, change in index refraction and photorefractive
sensitivity. The results are good and the crystal can be used for optical data
storage, dynamic holography, etc. For a - wave mixing configuration,the
same crystal as a recording medium for real time displacement has been
used. For measurement of distant object a high coherent source such as He-
Ne laser has can been used. Long coherence length of the laser permit to
study the objects which are far away from the crystal. The influence of
intervening medium must be negligible.