Single particle tracking has found broad applications in the life and physical sciences, enabling the observation and characterisation of nano- and microscopic motion. Fluorescence-based approaches are ideally suited for high-background environments, such as tracking lipids or proteins in or on cells, due to superior background rejection. Scattering-based detection is preferable when localisation precision and imaging speed are paramount due to the in principle infinite photon budget. Here, we show that micromirror-based total internal reflection dark field microscopy enables background suppression previously only reported for interferometric scattering microscopy, resulting in nm localisation precision at 6 $μ$s exposure time for 20 nm gold nanoparticles with a 25 x 25 $μ$m$^{2}$ field of view. We demonstrate the capabilities of our implementation by characterizing sub-nm deterministic flows of 20 nm gold nanoparticles at liquid-liquid interfaces. Our results approach the optimal combination of background suppression, localisation precision and temporal resolution achievable with pure scattering-based imaging and tracking of nanoparticles at regular interfaces.
Dynamic axial focusing functionality has recently experienced widespread incorporation in microscopy, augmented/virtual reality (AR/VR), adaptive optics, and material processing. However, the limitations of existing varifocal tools continue to beset the performance capabilities and operating overhead of the optical systems that mobilize such functionality. The varifocal tools that are the least burdensome to drive (ex: liquid crystal, elastomeric or optofluidic lenses) suffer from low (~ 100 Hz) refresh rates. Conversely, the fastest devices sacrifice either critical capabilities such as their…
Single-pixel imaging (SPI) has attracted widespread attention because it generally uses a non-pixelated photodetector and a digital micromirror device (DMD) to acquire the object image. Since the modulated patterns seen from two reflection directions of the DMD are naturally complementary, one can apply complementary balanced measurements to greatly improve the measurement signal-to-noise ratio and reconstruction quality. However, the balance between two reflection arms significantly determines the quality of differential measurements. In this work, we propose and demonstrate a simple secondar…
Surface topology measurements of micro- or nanostructures is essential for both scientific and industrial applications. However, high-throughput measurements remain challenging in surface metrology. We present a single-shot full-field surface topography measurement using Kramers-Kronig holographic imaging and spectral multiplexing. Three different intensity images at different incident angles were simultaneously measured with three different colors, from which a quantitative phase image was retrieved using spatial Kramers-Kronig relations. A high-resolution topographic image of the sample was …
Korea Advanced Institute of Science and Technology (KAIST)（韩国科学技术院）；KAIST Institute for Health Science and Technology, KAIST（韩国科学技术院健康科学与技术研究所）；Graduate School of Medical Science and Engineering, KAIST（韩国科学技术院医学科学与工程研究生院）；Department of Mechanical Engineering, KAIST（韩国科学技术院机械工程系）；Graduate School of Stem Cell and Regenerative Biology, KAIST（韩国科学技术院干细胞与再生生物学研究生院）；Department of Pathology, Gangnam Severance Hospital, Yonsei University College of Medicine（延世大学医学院江南世福兰斯医院病理科）；Center for Genome Engineering, Institute for Basic Science（基础科学研究院基因组工程中心）；BioMedical Research Center (BMRC), KAIST（韩国科学技术院生物医学研究中心）；Tomocube Inc.（Tomocube公司）
The University of Queensland（昆士兰大学）；ARC Centre of Excellence in Quantum Biotechnology（量子生物技术卓越中心）；Queensland Brain Institute（昆士兰大脑研究所）；RMIT University（皇家墨尔本理工大学）；University of Otago（奥塔哥大学）
Structured illumination microscopy using a photonic chip
结构化照明显微镜（SIM）能够以高速实现活细胞超分辨率成像。SIM使用复杂的光学系统来产生预定的激发光图案，并使用重建算法来将分辨率提高到两倍。SIM的光学设置依赖于精密的自由空间光学器件来产生光图案，以及高数值孔径物镜来将图案投射到样品上。这些布置易于失准，通常具有高成本，并且最终分辨率增强受到收集光学器件的数值孔径的限制。在这里，我们提出了一种基于光子芯片的全内反射荧光（TIRF）-SIM，大大降低了采集TIRF-SIM图像所需的光学设置的复杂性。这是通过从显微镜取出光传输并将其传输到光子芯片来实现的。传统的载玻片被平面光子芯片所取代，既可以容纳样品又可以照亮样品。该芯片用于产生一个驻波干涉图案，该图案通过倏逝场照射样品。通过使用热光调制来控制干涉图案的相位，从而使SIM系统的光照射路径的覆盖区为大约4 × 4 cm $^2$。此外，我们表明，通过使用的光子芯片技术，SIM的分辨率增强可以增加以上的传统方法。此外，通过分离激发和收集光路，该技术打开了使用低数值物镜的可能性，而不会牺牲SIM分辨率。基于芯片的SIM代表了一种简单，稳定和负担得起的方法，它可以使该技术的广泛渗透，也可能为高通量光学超分辨率显微镜开辟道路。
Total internal reflection fluorescence microscopy (TIRF) has enabled low-background, live-cell friendly imaging of cell surfaces and other thin samples thanks to the shallow penetration of the evanescent light field into the sample. The implementation of TIRF on optical waveguide chips (c-TIRF) has overcome historical limitations on the magnification and field of view (FOV) compared to lens-based TIRF, and further allows the light to be guided in complicated patterns that can be used for advanced imaging techniques or selective stimulation of the sample. However, the opacity of the chips thems…
The physical properties of two-dimensional (2D) materials may drastically vary with their thickness profiles. Current thickness profiling methods for 2D material (e.g., atomic force microscopy and ellipsometry) are limited in measurement throughput and accuracy. Here we present a novel high-speed and high-precision thickness profiling method, termed Transmission-Matrix Quantitative Phase Profilometry (TM-QPP). In TM-QPP, picometer-level optical pathlength sensitivity is enabled by extending the photon shot-noise limit of a high sensitivity common-path interferometric microscopy technique, whil…
The imaging depth of deep-tissue optical microscopy is governed by the performance of the gating operation that suppresses the multiply scattered waves obscuring the ballistic waves. Although various gating operations based on confocal, time-resolved/coherence-gated, and polarization-selective detections have proven to be effective, each has its own limitation; certain types of multiply scattered waves can bypass the gating. Here, we propose a method, volumetric gating, that introduces ultrasound focus to confocal reflectance imaging to suppress the multiply scattered waves traveling outside t…
