The pulse profile influence of excitation light on the two-photon absorption coefficient \beta is theoretically and numerically studied. Based on Gaussian spatial and temporal laser, we obtain an expansion formula of energy transmission. As compared with a plain beam and a pulse beam that is rectangular in time but Gaussian in space, the relative deviations of \beta turn out to be about 214% and 47%, respectively. These differences indicate that a smaller \beta may be obtained than the real one in usual nonlinear transmission. Our result suggests that by taking real pulse profile into account, a more exact \beta can be derived in energy transmission measurement.
© 2010 Chinese Optics Letters
(020.4180) Atomic and molecular physics : Multiphoton processes
(160.4330) Materials : Nonlinear optical materials
(190.4710) Nonlinear optics : Optical nonlinearities in organic materials
(140.3538) Lasers and laser optics : Lasers, pulsed
Peide Zhao, Yong Zhang, Wenxia Bao, Zhongya Zhang, Dayun Wang, Ming Liu, and Zhidong Zhang, "Quantitative deviation of the two-photon absorption coefficient based on three laser pulse models," Chin. Opt. Lett. 8, 93-98 (2010)