近日，新加坡国立大学的Zhiwei Huang及其研究团队取得一项新进展。经过不懈努力，他们利用反传播超低贝塞尔光弹生成研制出飞行时间分辨受激拉曼散射显微镜。相关研究成果已于2024年7月1日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队提出了一种新型的飞行时间分辨率贝塞尔光弹级受激拉曼散射(B²-SRS)显微镜，用于高分辨率的深层组织三维化学成像，无需机械z扫描。为了完成这项任务，研究人员设想了一种独特的方法，通过在样品中产生反传播泵浦和斯托克斯贝塞尔光弹来实现光学切割，其中贝塞尔光弹的群速度是超低的(例如v_g≈0.1c)，并通过引入可编程角色散与空间光调制器来调节。研究人员从理论上分析了共线多色贝塞尔光弹的工作原理和速度控制以及相对飞行时间分辨检测在SRS三维深部组织成像中的应用。

研究人员还建立了B²-SRS成像系统，并首次展示了使用贝塞尔光弹的B²-SRS显微镜在各种样品(例如聚合物珠幻象，生物样品如葱组织和猪脑)中进行高分辨率的3D化学成像。与传统的SRS显微镜相比，B²-SRS技术在猪脑组织成像深度上提供了2倍以上的改善。B²-SRS开发的利用反传播超低贝塞尔光弹在组织中进行光学切片的方法是通用的，易于执行，并且可以很容易地扩展到其他非线性光学成像模式，以推进生物和生物医学系统等领域的三维显微成像。

附：英文原文

Title: Time-of-flight resolved stimulated Raman scattering microscopy using counter-propagating ultraslow Bessel light bullets generation

Author: Lin, Shulang, Gong, Li, Huang, Zhiwei

Issue&Volume: 2024-07-01

Abstract: We present a novel time-of-flight resolved Bessel light bullet-enabled stimulated Raman scattering (B²-SRS) microscopy for deeper tissue 3D chemical imaging with high resolution without a need for mechanical z-scanning. To accomplish the tasks, we conceive a unique method to enable optical sectioning by generating the counter-propagating pump and Stokes Bessel light bullets in the sample, in which the group velocities of the Bessel light bullets are made ultraslow (e.g., v_g≈0.1c) and tunable by introducing programmable angular dispersions with a spatial light modulator. We theoretically analyze the working principle of the collinear multicolor Bessel light bullet generations and velocity controls with the relative time-of-flight resolved detection for SRS 3D deep tissue imaging. We have also built the B2-SRS imaging system and present the first demonstration of B²-SRS microscopy with Bessel light bullets for 3D chemical imaging in a variety of samples (e.g., polymer bead phantoms, biological samples such as spring onion tissue and porcine brain) with high resolution. The B²-SRS technique provides a>2-fold improvement in imaging depth in porcine brain tissue compared to conventional SRS microscopy. The method of optical sectioning in tissue using counter-propagating ultraslow Bessel light bullets developed in B2-SRS is generic and easy to perform and can be readily extended to other nonlinear optical imaging modalities to advance 3D microscopic imaging in biological and biomedical systems and beyond.

DOI: 10.1038/s41377-024-01498-y

Source: https://www.nature.com/articles/s41377-024-01498-y