Fig. 1. Curves of phase retardation angle Θ induced by elliptical birefringence in BSO20 crystal versus applied voltage U

Fig. 2. Curves of π-voltage Uπ and π/2-voltage Uπ/2 of BSO20 crystal versus its length L

Fig. 3. Curved surface of phase retardation angle Θ induced by elliptical birefringence in BSO20 crystal versus crystal length L and applied voltage U

Fig. 4. Curved surface of light intensity transmittance f(U,α) versus applied voltage U and azimuth angle α of analyzer

Fig. 5. Curved surface of light intensity transmittance versus crystal length L and applied voltage U. (a) f(U,0); (b) f(U,45)

Fig. 6. Curves of light intensity transmittance versus applied voltage U for different crystal length L. (a) f(U,0); (b) f(U,45)

Fig. 7. Experimental setup for measurement of π/4-voltage of BSO20 crystal

Fig. 8. Experimental data of output voltage Uodc versus the applied dc voltage Udc and their sinusoidal fitting curves

Fig. 9. Curves of df(U,0)/dU versus applied voltage U for different crystal lengths