FDTD Analysis of Ultra Short Pulse Laser Propagation in Transient Lens Effect

Recent advances in measurement techniques using the photo-thermal effect have drawn attention to the application in various fields. We focus on the transient lens effect, which is a well-known photo-thermal phenomenon. As this effect is caused by the change of thermal properties or other physical properties, the measurements using this effect have the possibility to measure various materials information. This phenomenon has the optical property of a concave lens since the refractive index distribution on the optical axis is formed when the sample is irradiated. One reason for the refractive index distribution in sample is the effect of the nonlinear effect when irradiated by ultra-short pulse laser. In this research, we investigate two-dimensional propagation of ultra short pulse laser in the sample with nonlinear effect by using FDTD method. Effect of the third-order susceptibility on the two-dimensional pulse propagation has been demonstrated.