Theoretical study on the closed-aperture Z-scan curves in the materials with nonlinear refraction and strong nonlinear absorption

详细信息    查看全文

• 作者：Liu ; Xiaodong ; Guo ; Shengli ; Wang ; Huitian ; Hou ; Lantian
• 关键词：42.65 ; 78.20 ; Nonlinear optics ; Z-scan ; Nonlinear refraction ; Nonlinear absorption
• 刊名：Optics Communications
• 出版年：2001
• 出版时间：October 1, 2001
• 年：2001
• 卷：197
• 期：4-6
• 页码：431-437
• 全文大小：123 K

文摘

The features of the closed-aperture (CA) Z-scan transmittance curves have been studied in detail when the third-order nonlinear refraction and absorption, both of which can be independently positive or negative, are simultaneously present. We found that whether the peak–valley or valley–peak structure exists or not, depends on the ratio ρ of the imaginary part χ_I⁽³⁾ to the real part χ_R⁽³⁾ of the third-order nonlinear susceptibility χ⁽³⁾ which are caused by nonlinear refraction and absorption respectively. This communication also gives the ρ dependences of the distance between the peak position and valley position, the difference between peak transmittance and the valley transmittance, the ratio of peak height to the valley depth for CA Z-scan, and especially the exact critical value ρ_c which determines whether the peak–valley or valley–peak structure exists or not, with Gaussian beams for the first time to our knowledge.