In this work, a thorough analysis of hyperosmotic agents for the immersion optical clearing (IOC) in terahertz (THz) range was performed. It was aimed at the selection of agents for the efficient enhancement of penetration depth of THz waves into biological tissues. Pulsed spectroscopy in the frequency range of 0.1 to 2.5 THz was applied for investigation of the optical properties of common IOC agents. Using the collimated transmission spectroscopy in visible range, binary diffusion coefficients of tissue water and agent in ex vivo rat brain tissue were measured. IOC agents were objectively compared using two‐dimensional nomogram, accounting for their THz‐wave absorption coefficients and binary diffusion coefficients. The results of this study demonstrate an interplay between the penetration depth enhancement and the diffusion rate and allow for pointing out glycerol as an optimal agent among the considered ones for particular applications in THz biophotonics.

中文翻译：

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太赫兹生物光子学中用于组织浸没光学清除的最佳高渗剂。

在这项工作中，对太赫兹（THz）范围内的浸没式光学清除（IOC）的高渗剂进行了彻底的分析。目的在于选择有效提高太赫兹波对生物组织的穿透深度的药剂。在0.1至2.5 THz频率范围内的脉冲光谱法被用于研究普通IOC试剂的光学性质。使用可见光范围内的准直透射光谱，测量离体大鼠脑组织中组织水和药剂的二元扩散系数。使用二维列线图客观地比较了IOC剂，考虑了它们的THz波吸收系数和二元扩散系数。