Glaser Adam K, Chen Ye, Liu Jonathan T C
Department of Mechanical Engineering, University of Washington, Seattle, WA, USA.
Optica. 2016;3(8):861-869. doi: 10.1364/OPTICA.3.000861.
Current simulation methods for light transport in biological media have limited efficiency and realism when applied to three-dimensional microscopic light transport in biological tissues with refractive heterogeneities. We describe here a technique which combines a beam propagation method valid for modeling light transport in media with weak variations in refractive index, with a fractal model of refractive index turbulence. In contrast to standard simulation methods, this fractal propagation method (FPM) is able to accurately and efficiently simulate the diffraction effects of focused beams, as well as the microscopic heterogeneities present in tissue that result in scattering, refractive beam steering, and the aberration of beam foci. We validate the technique and the relationship between the FPM model parameters and conventional optical parameters used to describe tissues, and also demonstrate the method's flexibility and robustness by examining the steering and distortion of Gaussian and Bessel beams in tissue with comparison to experimental data. We show that the FPM has utility for the accurate investigation and optimization of optical microscopy methods such as light-sheet, confocal, and nonlinear microscopy.
当前用于生物介质中光传输的模拟方法，在应用于具有折射不均匀性的生物组织中的三维微观光传输时，效率和真实感有限。我们在此描述一种技术，该技术将适用于模拟折射率变化较弱的介质中光传输的光束传播方法与折射率湍流的分形模型相结合。与标准模拟方法相比，这种分形传播方法（FPM）能够准确且高效地模拟聚焦光束的衍射效应，以及组织中存在的导致散射、折射光束转向和光束焦点像差的微观不均匀性。我们验证了该技术以及FPM模型参数与用于描述组织的传统光学参数之间的关系，并通过将高斯光束和贝塞尔光束在组织中的转向和畸变与实验数据进行比较，展示了该方法的灵活性和稳健性。我们表明，FPM对于诸如光片显微镜、共聚焦显微镜和非线性显微镜等光学显微镜方法的精确研究和优化具有实用价值。
