An all-optical wavelength conversion based on the cascaded second-order nonlinear interactions of Sum-and Difference-Frequency Generation(SFG+DFG) in quasi-phase matched Periodically Poled LiNbO_3(PPLN) Waveguides with a dual-pulse pump source is studied.

It was speculated therefore,the“six site potential”is not very appreciative for describing the polarization reversal in these ferroelectric copolymers.

By means of impedance analyzer and iterative method, the polarization reversal process of Pb (Mg1/3Nb2/3)0.

The polarization reversal characteristics of(Pb1-xSrx)TiO3 ferroelectric thin films were measured by square-wave voltage with double polarity and double impulse.

A nonlinear constitutive model for piezoelectric ceramics is proposed, in which the polarization switching and electric saturation are taken into account.

In this work, the influences of thickness and grain size on ferroelectric, polarization switching current have been studied in experiments and theoretical analyses.

The electron emission from the diode is the result of polarization switching of the ferroelectric cathode.

An equivalent circuit of ferroelectrics in response with fast and slow polarization effect was given, and can be used to analyze the polarization switch signal of TGS crystal.

Dynamics theory of ferroelectric polarons, which was developed from the shielding theory of ferroelectricity, is used to explain the polarization switch of ferroelectricity.

The refractive index changes induced by the linear electro-optic effect in normal-poled and reverse-poled LiNbO_3 wave-guides were calculated,and the results that show the refractive index changes in two arms are opposite to each other when the electric field is applied in +z direction,which agree with the experimental results.