Z-scan theory with simultaneous two- and three-photon absorption saturation

We report a theoretical investigation of the open-aperture Z-scan technique for an optically thin medium with simultaneous saturation of both two- and three-photon absorption. By using the Adomian decomposition method (ADM), we obtain the analytical expression for the normalized transmittance of the open-aperture Z-scan traces. Furthermore, the analytical results are good agreement with the numerical simulations. The results indicate that ADM is an effective yet quickly approach to evaluate the saturable properties originating from both two- and three-photon absorption.

► We study Z-scan theory with simultaneous two- and three-photon absorption saturation. ► We present the analytical expression of Z-scan normalized transmittance by using ADM. ► We compare the analytical results with numerical simulations. ► We prove the validity of our theory. ► We discuss how to estimate the saturable absorption parameters from Z-scan traces.