In this work, different sizes of BaTiO3 (BTO) were characterized. The effective parameters were studied to reach optimum performance in order to realize an optical modulator. The parameters such as spectroscopy, electro-optic coefficient, crystalline structure, and birefringence indicated that BaTiO3 has an excellent behavior to manipulate the light by Pockels modulator, spatially in the field of telecom. The sample size (10×3 mm) was shown a good performance compare with other samples, for example, the BTO has low absorption, high variation of output as a function of voltage applied and good efficiency that showed by figure of merit. In addition, a low half-wave voltage (Vπ) was observed.