Z-scan theory for material with two- and three-photon absorption.
We present a theoretical study on the Z-scan characteristics of thin nonlinear optical media with simultaneous two- and three-photon absorption, a situation that exists, for example, in polydiacetylenes. With the introduction of a coupling function between two- and three-photon absorption, we find a quasi-analytic expression for open aperture Z-scan traces. We make a comparison of the analytic solutions with numerical solutions in detail, showing that they are in good agreement. This theoretical result allows us to easily identify and determine simultaneously the two- and three-photon absorption coefficients from the open aperture Z-scan traces.
Gu
Bing
B
Wang
Jin
J
Chen
Jing
J
Fan
Ya-Xian
YX
Ding
Jianping
J
Wang
Hui-Tian
HT