近日，英国阿斯顿大学的Igor Meglinski与芬兰奥卢大学的Alexander Bykov等人合作并取得一项新进展。经过不懈努力，他们实现多重散射环境下光轨道角动量的相位保持。相关研究成果已于2024年8月26日在国际知名学术期刊《光：科学与应用》上发表。

波前整形技术的最新进展促进了人们对具有轨道角动量（OAM）的复杂结构光在各种介质中传播的研究。拉盖尔-高斯（LG）光束在其近轴传播过程中引入螺旋相位调制，得益于介质折射率随时间变化的负梯度，导致相位扭曲速率显著增加，有效地观察到OAM的相位延迟。

该方法对介质折射率的微小变化（～10^-6）具有显著的敏感性。OAM的相位记忆表现为扭曲光即使在通过浑浊类组织的多次散射介质传播时，也能保持初始的螺旋相位。这项研究结果证实了将OAM光应用于生物医学领域的有趣机会，例如无创经皮葡萄糖检测和通过生物组织及其他光学密集介质的光通信。

附：英文原文

Title: Phase preservation of orbital angular momentum of light in multiple scattering environment

Author: Meglinski, Igor, Lopushenko, Ivan, Sdobnov, Anton, Bykov, Alexander

Issue&Volume: 2024-08-26

Abstract: Recent advancements in wavefront shaping techniques have facilitated the study of complex structured light’s propagation with orbital angular momentum (OAM) within various media. The introduction of spiral phase modulation to the Laguerre–Gaussian (LG) beam during its paraxial propagation is facilitated by the negative gradient of the medium’s refractive index change over time, leading to a notable increase in the rate of phase twist, effectively observed as phase retardation of the OAM. This approach attains remarkable sensitivity to even the slightest variations in the medium’s refractive index (～10^-6). The phase memory of OAM is revealed as the ability of twisted light to preserve the initial helical phase even propagating through the turbid tissue-like multiple scattering medium. The results confirm fascinating opportunities for exploiting OAM light in biomedical applications, e.g. such as non-invasive trans-cutaneous glucose diagnosis and optical communication through biological tissues and other optically dense media.

DOI: 10.1038/s41377-024-01562-7

Source: https://www.nature.com/articles/s41377-024-01562-7