肥皂膜中光分支流现象的探究

BRANCHED FLOW OF LIGHT IN THIN SOAP MEMBRANES

光通过弱无序散射介质时可产生分支流现象。针对激光在肥皂液薄膜中的传播,本文利用分步傅里叶变换方法数值求解等效薛定谔方程,探究了光波长、肥皂液浓度、肥皂膜厚度等因素对光分支现象的影响。理论分析及数值计算显示,有效势场变化幅度越大、关联长度越小,分支现象越明显;相应地,激光波长越小、肥皂液浓度越高、肥皂膜厚度变化幅度越大、厚度变化关联长度越小,则分支现象越明显。在此基础上,我们通过实验验证了多种参数对光的分支现象的影响,得到了与理论分析及数值计算相一致的结果。本研究理论与实验相辅相成,有助于学生理解光分支现象的产生机制,可作为创新性或居家物理实验教学参考。

When lights propagate through a weak disordered media,branched flow may occur.Regarding the propagation of laser lights in thin soap membranes,we adopt the split-step Fourier method for numerically solving the effective nonlinear Shrödinger equation,and explore the influence of light wavelength,soap concentration,soap film thickness and other factors on the optical branched flow phenomenon.Both theoretical analysis and numerical calculations show that branched flows are more significant when the variation amplitude of the effective potential field is larger,and the correlation length is smaller.Correspondingly,branched flows are more significant for laser lights with smaller wavelengths and soap membranes with higher concentrations,larger variations,or smaller correlation lengths of thickness.These results are further qualitatively confirmed by experiments.Combining theory with experiment,our work is helpful for students to understand the mechanism of light branching phenomenon,and can be used as an innovative or home physics experiment teaching reference.