Nonlinear optical properties in La-modified ( 1-x ) Pb ( Mg1/3Nb2/3 ) O3-xPbTiO3 (PMN-PT) (3/75/25) transparent ceramic are studied. The optical nonlinearity is investigated employing Z-scan technique at the off-resonant wavelengths of 515 and 1030 nm. The two-photon absorption coefficient is measured up to be 9.6 cm / GW at 515 nm, and three-photon absorption coefficient is found to be 0.091 cm3 / GW2 at 1030 nm. When an external electric field was applied to the PMN-PT, we found that the electric field increased from 0 to 3 kV / cm in the closed-aperture Z-scan experiment with the wavelength of 515 nm, whereas the nonlinear refractive index n2 increased from 1.85 × 10 − 8 esu to 3.87 × 10 − 8 esu, an increase of 110%. The large nonlinear effect could be applied in areas such as sensor protection and telecommunications and to write permanent refractive index structures into the interior of optical materials, which may make a difference in integrate optoelectronic devices progress.
Based on the propagation of Gaussian light, Zemax program is used to simulate the pump light propagating process and absorbing distribution for LDA side-pump laser rod,and the corresponding heat load distribution analysis of the rod is done by using Lascad program.On the basis of simulation results,the pump parameters of LDA side-pump Nd:YAG are optimized which provide valuable guidances for side-pump LDA designing and pump module engineering.