近日，瑞士苏黎世联邦理工学院Romain Quidant团队研究了光学活性的广角光谱成像。相关论文发表在2025年7月28日出版的《自然—光子学》杂志上。

光学活性光谱技术，如圆二色性和旋光色散，对于研究分子和材料的手性必不可少。然而，目前的方法往往难以分析异质性和空间变化的手性样品。一方面，光谱学方法虽然灵敏，但通常需要大量样品，并产生总体平均数据。另一方面，手性成像以耗费时间的共聚焦扫描和复杂的仪器为代价来提供空间分辨率。

为了解决这一问题，研究组推出了一个广域、光谱分辨光学成像的平台。使用偏振敏感离轴全息术同时捕获左圆和右圆偏振分量，该系统实现单次检索圆二色性和光学旋转色散图像，以及消除由线性各向异性填充的人工制品。该结果不仅与传统的圆二色光谱一致，而且还证明了在空间上解决由系综平均丢失的局部手性变化的能力，包括对映体过量。该平台对分析复杂的生物和材料样品具有很大的前景，扩大了手性表征的范围。

附：英文原文

Title: Wide-field spectroscopic imaging of optical activity

Author: Bchner, Rebecca, Garca-Guirado, Jose, Ortega Arroyo, Jaime, Quidant, Romain

Issue&Volume: 2025-07-28

Abstract: Optical activity spectroscopy techniques, such as circular dichroism and optical rotatory dispersion, are essential for investigating the chiral properties of molecules and materials. However, current methods often struggle to analyse heterogeneous and spatially varying chiral samples. On one hand, spectroscopic approaches, although sensitive, often require large sample volumes and produce ensemble-averaged data. On the other hand, chiral imaging delivers spatial resolution at the expense of time-consuming confocal scanning and complex instrumentation. Addressing this gap, we introduce a platform for wide-field, spectrally resolved optical activity imaging. Using polarization-sensitive off-axis holography to simultaneously capture left- and right-circularly polarized components, our system allows the single-shot retrieval of circular dichroism and optical rotatory dispersion images, as well as eliminating artefacts caused by linear anisotropies. Our results are not only consistent with traditional circular dichroism spectroscopy but also demonstrate the ability to spatially resolve local chirality variations lost by ensemble averaging, including enantiomeric excess. This platform holds great promise for analysing complex biological and material samples, expanding the scope of chiral characterization.

DOI: 10.1038/s41566-025-01722-0

Source: https://www.nature.com/articles/s41566-025-01722-0