Opt Lett. 2023 Apr 15;48(8):2058-2061. doi: 10.1364/OL.488675.
In this Letter, we report a dual-wavelength Mueller matrix imaging system for polarization phase unwrapping, allowing simultaneous acquisition of the polarization images at 633 nm and 870 nm. After phase unwrapping, the relative error of linear retardance is controlled to be 3% and the absolute error of birefringence orientation is about 6°. We first show that polarization phase wrapping occurs when the samples are thick or present obvious birefringence effects, and further analyze the effect of phase wrapping on anisotropy parameters via Monte Carlo simulations. Then, experiments on porous alumina with different thicknesses and multilayer tapes are performed to verify the feasibility of phase unwrapping by a dual-wavelength Mueller matrix system. Finally, by comparing the temporal characteristics of linear retardance during tissue dehydration before and after phase unwrapping, we emphasize the significance of the dual-wavelength Mueller matrix imaging system not only for anisotropy analysis in static samples, but also for determining the trend in polarization properties of dynamic samples.
在这封信件中，我们报告了一种用于偏振相位解缠的双波长 Mueller 矩阵成像系统，可同时获取 633nm 和 870nm 处的偏振图像。相位解缠后，线性延迟的相对误差控制在 3%以内，双折射方向的绝对误差约为 6°。我们首先表明，当样品较厚或存在明显的双折射效应时，偏振相位会发生缠绕，并通过蒙特卡罗模拟进一步分析相位缠绕对各向异性参数的影响。然后，对具有不同厚度的多孔氧化铝和多层胶带进行了实验，以验证双波长 Mueller 矩阵系统相位解缠的可行性。最后，通过比较组织在解缠前后脱水过程中线性延迟的时间特性，我们强调了双波长 Mueller 矩阵成像系统的重要性，不仅可用于分析静态样品的各向异性，还可用于确定动态样品偏振特性的趋势。
