Fluorescence imaging in the second near-infrared window (NIR-II, 900–1880nm) with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imaging with high spatial resolution. However, the traditional NIR-II fluorescence confocal microscope with separate excitation focus and detection pinhole makes it possess low confocal efficiency, as well as difficultly to adjust. Two types of upgraded NIR-II fluorescence confocal microscopes, sharing the same pinhole by excitation and emission focus, leading to higher confocal efficiency, are built in this work. One type is fiber-pinhole-based confocal microscope applicable to CW laser excitation. It is constructed for fluorescence intensity imaging with large depth, high stabilization and low cost, which could replace multiphoton fluorescence microscopy in some applications (e.g., cerebrovascular and hepatocellular imaging). The other type is air-pinhole-based confocal microscope applicable to femtosecond (fs) laser excitation. It can be employed not only for NIR-II fluorescence intensity imaging, but also for multi-channel fluorescence lifetime imaging to recognize different structures with similar fluorescence spectrum. Moreover, it can be facilely combined with multiphoton fluorescence microscopy. A single fs pulsed laser is utilized to achieve up-conversion (visible multiphoton fluorescence) and down-conversion (NIR-II one-photon fluorescence) excitation simultaneously, extending imaging spectral channels, and thus facilitates multi-structure and multi-functional observation.

本文针对单晶硅在不同温度、浓度、表面活性剂等多种刻蚀条件下的形貌模拟问题, 构建了硅原子结构模型并分析了其主要晶面刻蚀速率和对应原子结构之间的关系, 提出了适应于单晶硅刻蚀模拟的表层原子刻蚀函数(Si-RPF), 明确了晶面宏观刻蚀速率与原子微观移除概率之间的数值联系, 构建了基于遗传算法的动力学蒙特卡罗各向异性湿法刻蚀工艺模型(Si-KMC)。该工艺模型可以基于台阶流动理论,从原子角度解释单晶硅刻蚀各向异性的成因, 能够明确不同类型的原子在刻蚀过程中的作用和实现对不同刻蚀条件下单晶硅衬底三维刻蚀形貌的精确模拟。对比有无表面活性剂添加条件下的单晶硅刻蚀实验数据和模拟结果表明, Si-KMC刻蚀工艺仿真模型模拟结果可以达到90%以上仿真精度。

当前蓝宝石各向异性刻蚀规律还没有获得完整揭示, 其刻蚀微结构演化过程和形貌结构很难实现准确预测和控制, 给蓝宝石衬底图案化结构加工成型和质量控制带来很大的挑战。本研究基于蓝宝石全晶面刻蚀速率实验数据, 详细分析了其微结构刻蚀成型过程和刻蚀机理, 并对比分析了刻蚀条件对蓝宝石刻蚀微结构和表面形貌的影响规律, 实验结果表明: 适当提高刻蚀温度可以提高刻蚀效率, 但会引起表面质量的下降; 以磷酸为代表的弱电解质类作为刻蚀缓冲剂能够有效提高刻蚀结构面质量; (275±10) ℃, 98%H2SO4∶85%H3PO4(体积配比)=3∶1刻蚀溶液可以获得最优的刻蚀速率和表面质量。

Lipid droplets (LDs) participate in many physiological processes, the abnormality of which will cause chronic diseases and pathologies such as diabetes and obesity. It is crucial to monitor the distribution of LDs at high spatial resolution and large depth. Herein, we carried three-photon imaging of LDs in fat liver. Owing to the large three-photon absorption cross-section of the luminogen named NAP-CF₃ (1.67×10 − 79cm⁶ s²), three-photon fluorescence fat liver imaging reached the largest depth of 80μm. Fat liver diagnosis was successfully carried out with excellent performance, providing great potential for LDs-associated pathologies research.

近年来，面向生物组织大深度光学成像的方法不断发展，其中包括光学相干层析、多光子成像和自适应光学等。介绍了浙江大学光电科学与工程学院近年来在生物组织大深度定量光学成像方面的一系列重要进展，包括光学相干层析结构与功能成像、基于三光子荧光显微的大深度脑血管成像和新型的畸变误差波前校正方法等，并进一步概述了如何对上述方法获取的光学图像实施定量表征以获取生物组织的生理与病理信息。