近日，意大利米兰国家研究委员会Franco V. A. Camargo团队报道了超快全息显微术。2026年4月8日出版的《自然—光子学》杂志发表了这项成果。
尽管在各类材料的输运与无序研究中，时空分辨率是理想特性，但目前尚无能够在大视场下对超快手性光学响应进行成像的技术。
研究组报道了一种利用飞秒脉冲复用离轴全息的宽场超快手性显微镜。通过将探测脉冲的水平与垂直偏振分量编码到傅里叶空间的不同位置，研究组能够完整获取宽场图像每个像素点的偏振椭圆信息。这使得重建包含旋光色散和圆二色性的瞬态复数值手性光学图像成为可能。此外，他们还获得了两个正交探测偏振分量的瞬态吸收和瞬态相位图像，从而实现了在大视场（50×50 µm2）内、具有高时间（约100飞秒）和高空间（亚微米）分辨率下对超快手性光学响应的完整表征。
研究组通过对杂化有机-无机钙钛矿中的自旋弛豫进行成像，展示了该技术的能力。最后，利用衍射极限激发光斑矩阵研究了多位点自旋扩散。该方法能够对涵盖生物分子、手性等离子体纳米结构、拓扑及自旋电子学材料在内的多种新兴功能材料中的瞬态磁学与电子学现象进行时空成像。
附：英文原文
Title: Ultrafast holographic chiroptical microscopy
Author: Hrmann, Martin, Visentin, Federico, Gessner, Julia A., Kollenz, Philipp, Liu, Shangpu, Heindl, Markus, Deschler, Felix, Cerullo, Giulio, Camargo, Franco V. A.
Issue&Volume: 2026-04-08
Abstract: Although spatiotemporal resolution is desirable for studies on transport and disorder in various materials, there is currently no technique for imaging ultrafast chiroptical responses over large fields of view. Here we report widefield ultrafast chiroptical microscopy using multiplexed off-axis holography with femtosecond pulses. By encoding the horizontal and vertical polarization components of the probe pulse at different positions in Fourier space, we fully retrieve the polarization ellipse for each pixel of a widefield image. This enables the reconstruction of transient complex-valued chiroptical images, which consist of optical rotatory dispersion and circular dichroism. In addition, we obtain images of the transient absorption and transient phase for the two orthogonal probe polarization components, thereby achieving a complete characterization of the ultrafast chiroptical response over a wide field of view (50×50μm2) with high temporal (~100-fs) and spatial (submicrometre) resolution. We demonstrate the capabilities of our technique by imaging spin relaxation in hybrid organic–inorganic perovskites. Finally, we study multisite spin diffusion using a matrix of diffraction-limited excitation spots. Our approach enables the spatiotemporal mapping of transient magnetic and electronic phenomena in a wide range of emerging functional materials, spanning biomolecules, chiral plasmonic nanostructures, and topological and spintronic materials.
DOI: 10.1038/s41566-025-01824-9
Source: https://www.nature.com/articles/s41566-025-01824-9