Final Question 4:

(20)4. A transverse phase EO modulator is fabricated with a 10x10 micron^2 LiNbO3 waveguide. The waveguides length is 1 cm. Calculate the voltage needed for a pi phase shift. Pay attention to the direction of the modulating electric field, the crystal symmetry and the polarization of the propagating electromagnetic field. Assume lambda=1 um. Make a sketch of all relevant field vectors. The electro optic coefficient matrix of LiNbO3 is:

0 -r22 r13

0 r22 r13

0 0 r33

0 r51 0

r51 0 0

-r22 0 0