title: Discriminating thermal effect in nonlinear-ellipse-rotation-modified Z-scan measurements.
abstract: We report that a modified Z-scan method by nonlinear ellipse rotation (NER) can be used to discriminate true nonlinear refraction from thermal effect in the transient regime and steady state. The combination of Z-scan and NER allows us to measure the third-order nonlinear susceptibility component without the influence of thermal-optical nonlinearity. The experimental results of pure CS(2) and CS(2) solutions of nigrosine verify that the transient thermal effect can be successfully eliminated from the NER-modified Z-scan measurements. This method is also extended to the case in which thermal-optical nonlinearities depend on a high repetition rate of femtosecond laser pulses for the N,N-dimethylmethanamide solutions of graphene oxide.
authors.affiliation: The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, Teda Applied Physics School, Nankai University, Tianjin 300457, China.
authors.forename: Zhi-Bo
authors.initials: ZB
authors.lastname: Liu
authors.forename: Shuo
authors.initials: S
authors.lastname: Shi
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Yan
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Zhou
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Tian