Beam waist changes in lithium niobate during Z-scan measurement

Abstract
The nonlinear propagation of Gaussian beams in LiNbO3 has been investigated using the Z‐scan technique. Experimental results shown that the minimum beam waist has been broadened. The third‐order optical nonlinearity χ(3) of LiNbO3 has been measured at 514 nm and found for the real and imaginary parts of the nonlinearity to be −1.7×10−5 and −4.3×10−6 esu, respectively.