The study of the modulation method for the KDP type crystals based on electro-optic effect

For the describe problems of the crystal electro-optic effect in the physical mechanism, the strict derivation method was put forward. The method was from the four Maxwell´s equations. The Taylor expansion was used and the higher order small magnitudes were omitted. The Pockels effect was deduced when the crystal was add the voltage. The new coordinate system was obtained from the method the coordinate system was rotating 45 degree angle along the z axis direction. The experimental results were shown that the result of the electro-optic modulation method was same as the result of the 1/4 wave plate when the crystal was add the voltage. The voltages were 3838.4V and 4198.8V for KDP in the wavelengths of 546.1nm and 632.8nm respectively. The voltage was 1485.8V for DKDP in the wavelengths of 546.1nm. The elliptical polarized light which was obtained by the spin light crystal form line polarized light was turned into line polarized light when the crystal was add the voltages.