Optical techniques

  • Article
    | Open Access

    Molecular orientation is often ignored during single-molecule localisation microscopy. Here, the authors use a Vortex point spread function in order to simultaneously estimate the 3D position, dipole orientation and degree of rotational constraint, within 30% of the Cramér-Rao bound limit.

    • Christiaan N. Hulleman
    • , Rasmus Ø. Thorsen
    •  & Bernd Rieger
  • Article
    | Open Access

    In classical wetting, the spreading of a drop on a surface is preceded by a bridge directly connecting the drop and the surface, yet it ignores the solubility of the drop phase in the medium. Here, the authors show that dissolved drop fluid from the parent drop can nucleate on the surface as islands, one of which coalesces with the parent drop to effect wetting.

    • Suraj Borkar
    •  & Arun Ramachandran
  • Article
    | Open Access

    The behaviour of Tungsten ditelluride (WTe2) in few-layer form is not yet fully characterized. Here the authors use a near-field terahertz microscopy technique to observe the electromagnetic responses of WTe2 flakes from one to several layers and to study their semimetallic/ semiconducting behavior.

    • Ran Jing
    • , Yinming Shao
    •  & D. N. Basov
  • Article
    | Open Access

    Cherenkov detectors are used to detect high energy particles and their performance capabilities depend heavily on the material used. Here, the authors propose use of a Brewster-optics-based angular filter for a detector with increased sensitivity and particle identification capability.

    • Xiao Lin
    • , Hao Hu
    •  & Yu Luo
  • Article
    | Open Access

    Light-driven micromotors can convert energy to motion in sub-millimeter dimensions. Here, the authors extend this concept and introduce reconfigurable micromachines with multiple components, driven by optoelectronic tweezers, and demonstrate new functionalities.

    • Shuailong Zhang
    • , Mohamed Elsayed
    •  & Aaron R. Wheeler
  • Article
    | Open Access

    The limit of X-ray detection is an important figure of merit for X-ray detectors, yet the suitability of method adopted from Currie’s 1968 paper and the following international standard is in doubt. Here, the authors propose a statistical model that correlates dark current and photo-current, show how it can be used to determine detection limit.

    • Lei Pan
    • , Shreetu Shrestha
    •  & Lei R. Cao
  • Article
    | Open Access

    Single-pixel holography generates holographic images with a single-pixel detector making this relatively inexpensive. Here the authors report a high-throughput single-pixel compressive holography method for imaging biological tissue which can either provide a large field of view or high resolution.

    • Daixuan Wu
    • , Jiawei Luo
    •  & Zhaohui Li
  • Article
    | Open Access

    Imaging rates in single-pixel imaging has been limited by the dependence on configurable spatial light modulators. Here, the authors use cyclic Hadamard patterns coded onto a spinning mask to demonstrate dynamic imaging with rates up to 72 frames per second and real time reconstruction capabilities.

    • Evgeny Hahamovich
    • , Sagi Monin
    •  & Amir Rosenthal
  • Article
    | Open Access

    The authors develop a method to build Manhattan Raman Scattering (MARS) probes based on different core atoms, conjugation ring numbers, and stable isotope substitutions. A quantitative model predicts vibrational frequencies of MARS dyes from structures, which are used in supermultiplexed vibrational imaging.

    • Yupeng Miao
    • , Naixin Qian
    •  & Wei Min
  • Article
    | Open Access

    Wavefront shaping is used to overcome scattering in biological tissues during imaging, but determining the compensation is slow. Here, the authors use holographic phase stepping interferometry, where new phase information is updated after each measurement, enabling fast improvement of the wavefront correction.

    • Molly A. May
    • , Nicolas Barré
    •  & Alexander Jesacher
  • Article
    | Open Access

    Frequency-comb-based multiheterodyne spectroscopy requires that total bandwidth of the measured spectrum covers less than half the comb spacing, which is usually not the case for incoherent spectra. Here, the authors propose a technique that lifts this requirement, and demonstrate it in the microwave regime.

    • David J. Benirschke
    • , Ningren Han
    •  & David Burghoff
  • Article
    | Open Access

    Light in disordered materials generates rich interference patterns called speckle, whose properties are known only on the outside of a sample. Here, the authors provide direct measurements and understanding of speckle generated inside a material, retrieving fundamental information that remained inaccessible up to now.

    • Marco Leonetti
    • , Lorenzo Pattelli
    •  & Giancarlo Ruocco
  • Article
    | Open Access

    Metasurfaces allow for vast possibilities of light control. Here, the authors demonstrate on-demand engineering and realization of a broad family of two-dimensional phase singularity sheets and transverse polarization singularity sheets, opening up new aspects of light-matter interaction.

    • Soon Wei Daniel Lim
    • , Joon-Suh Park
    •  & Federico Capasso
  • Article
    | Open Access

    Optoacoustic sensing applications are limited by weak electrostrictive force. Here, the authors induce photothermally acoustic vibrations with a focused pulsed laser, and via scanning demonstrate sensing of acoustic impedance at 10 µm spatial resolution, allowing for visualisation of diffusion dynamics.

    • Yizhi Liang
    • , Huojiao Sun
    •  & Bai-Ou Guan
  • Article
    | Open Access

    Hybrid perovskite is a promising class of material for optoelectronic applications due to the slow hot-carrier cooling, yet the process is not well-understood in material with Rashba band splitting. Here, the authors reveal spin-flipping and spin-dependent scattering of hot electrons are responsible for accelerating the cooling at longer delays.

    • Jun Yin
    • , Rounak Naphade
    •  & Omar F. Mohammed
  • Article
    | Open Access

    The authors present a microwave imaging system that can operate in continuous transmit-receive mode. Using an array of transmitters, a single receiver and a reconstruction matrix that correlate random time patterns with the captured signal, they demonstrate real-time imaging and tracking through a wall.

    • Fabio C. S. da Silva
    • , Anthony B. Kos
    •  & Archita Hati
  • Article
    | Open Access

    The authors demonstrate accurate localization in three dimensions by comprehensive calibration of an ordinary microscope, exploiting the latent information of intrinsic aberrations. Rigid transformation of the emitter positions tests the method and enables measurements in six degrees of freedom.

    • Craig R. Copeland
    • , Craig D. McGray
    •  & Samuel M. Stavis
  • Article
    | Open Access

    Direct visualisation of 3D vector distributions of photoinduced fields can shed light on the optical and mechanical behaviour of different materials. Here, the authors demonstrate such visualisation using photoinduced force microscopy by observing the optical gradient force at the nanometer scale.

    • Junsuke Yamanishi
    • , Hidemasa Yamane
    •  & Yasuhiro Sugawara
  • Article
    | Open Access

    Imaging through scattering media is possible using a transmission matrix or the memory effect. Here, the authors describe the nature of optical memory effects in structures of arbitrary geometry and use this framework to estimate the transmission matrix of an optical fibre from just one end.

    • Shuhui Li
    • , Simon A. R. Horsley
    •  & David B. Phillips
  • Article
    | Open Access

    It has been challenging to rotate nanoparticles orbitally via optical trapping beyond the diffraction limit. Here, the authors take advantage of the nonlinear optical effect and demonstrate fast and controlled orbital rotation at subwavelength scale with a femtosecond pulsed Gaussian beam.

    • Yaqiang Qin
    • , Lei-Ming Zhou
    •  & Yuqiang Jiang
  • Article
    | Open Access

    The Z-scheme photocatalytic system is promising for producing renewable energy by sunlight, but the optimization of multiple materials is challenging. Here, authors directly map out the photocatalytic activity on a microscopic scale by the clustering analysis for the time-resolved image sequence.

    • Makoto Ebihara
    • , Takeshi Ikeda
    •  & Kenji Katayama
  • Article
    | Open Access

    Light field prints displaying 3D information often appear pixelated due to limited resolution and misalignment between lenses and colour pixels. Here, the authors present a one-step process via two-photon polymerization lithography to fabricate light field prints with high spatial and angular resolution.

    • John You En Chan
    • , Qifeng Ruan
    •  & Joel K. W. Yang
  • Article
    | Open Access

    Super-resolution microscopy is often limited by photobleaching or uneven distribution of fluorophores. The authors present a label-free superresolution method termed VISTA, combining sample-expansion and vibrational imaging, with resolution down to 78 nm in protein-rich biological structures in cells and tissues.

    • Chenxi Qian
    • , Kun Miao
    •  & Lu Wei
  • Article
    | Open Access

    Studying dynamic processes in mechanobiology has been challenging due to lack of appropriate tools. Here, the authors present an interference-based method, illuminated via two rapidly alternating wavelengths, which enables real-time mapping of nanoscale forces with sub-second mechanical fluctuations.

    • Andrew T. Meek
    • , Nils M. Kronenberg
    •  & Malte C. Gather
  • Article
    | Open Access

    The need for space between lenses in optical systems results in a trade-off between potential for miniaturisation and achieved resolution. Here, the authors demonstrate a device that propagates light longer than its thickness, a spaceplate, and can therefore replace space in optical systems.

    • Orad Reshef
    • , Michael P. DelMastro
    •  & Jeff S. Lundeen
  • Article
    | Open Access

    Combining magnetic and semiconducting properties in a single material offers great technological potential, all the more so if these are coupled with good optical properties. Here, Neumann et al. present a Manganese doped Ruddlesden-Popper perovskite with this trifecta of attributes.

    • Timo Neumann
    • , Sascha Feldmann
    •  & Felix Deschler
  • Article
    | Open Access

    Tip-enhanced nano-spectroscopy suffers from inconsistent signal and difficulty in polarization-resolved measurement. Here, the authors present adaptive tip-enhanced nano-spectroscopy, which enables the additional signal enhancement and near-field polarization control via dynamic wavefront shaping.

    • Dong Yun Lee
    • , Chulho Park
    •  & Kyoung-Duck Park
  • Article
    | Open Access

    Here, the authors present a method for quantifying molecular interactions on a glass surface, based on measuring surface refractive index changes via the reflectivity near the critical angle. They demonstrate tunable sensitivity and dynamic range, deep vertical sensing range, also for intracellular signals.

    • Guangzhong Ma
    • , Runli Liang
    •  & Shaopeng Wang
  • Article
    | Open Access

    Currently relatively few functional probes for Raman-based live-cell profiling exist. Here the authors build on their previous ultra-bright Raman dots to devise a 14-plexed Raman probe panel to quantify cell surface proteins, endocytosis activities and metabolic dynamics of single live cells.

    • Chen Chen
    • , Zhilun Zhao
    •  & Wei Min
  • Article
    | Open Access

    It is difficult to apply SMLM to complex biological tissues. Here the authors report REALM, Robust and Effective Adaptive Optics in Localisation Microscopy, to improve SMLM in tissue and use this to resolve the organisation of spectrin in the axon initial segment in brain tissue.

    • Marijn E. Siemons
    • , Naomi A. K. Hanemaaijer
    •  & Lukas C. Kapitein
  • Article
    | Open Access

    Vibrational energy transfer (VET) is essential for protein function as it is responsible for efficient energy dissipation in reaction sites and is linked to pathways of allosteric communication. Here authors equipped a tryptophan zipper with a VET injector and a VET sensor for femtosecond pump probe experiments to map the VET.

    • Erhan Deniz
    • , Luis Valiño-Borau
    •  & Jens Bredenbeck
  • Article
    | Open Access

    Dielectric metasurfaces have different Q-factor and light localisation requirements for sensing and imaging. Here, the authors present a dielectric metasurface, supporting two optical modes with sharp Fano resonances for high Q-factors and strong spatial confinement, allowing both sensing and imaging.

    • Donato Conteduca
    • , Isabel Barth
    •  & Thomas F. Krauss
  • Article
    | Open Access

    The authors engineer a type of bound states in the continuum in diatomic dielectric metasurfaces, allowing for high-quality resonances with accessible enhanced fields. Metasurface microarrays are integrated with microfluidics on an imaging platform for real-time detection of biosamples, based on reconstructing spectral shift information.

    • Yasaman Jahani
    • , Eduardo R. Arvelo
    •  & Hatice Altug
  • Article
    | Open Access

    The authors introduce stochastic optical scattering localization imaging (SOSLI) for non-invasive super-resolution imaging through scattering media. They capture multiple speckle patterns of photo-switchable point sources and use the speckle correlation to retrieve images with 100 nm resolution.

    • Dong Wang
    • , Sujit K. Sahoo
    •  & Cuong Dang
  • Article
    | Open Access

    Probes with reversible fluorescence are useful in super-resolution microscopy, but lack sufficient chemical specificity. Here, the authors engineer alkyne tagged diarylethene to realize photo-switchable stimulated Raman scattering probes with high chemical resolution, for applications in living cells.

    • Jianpeng Ao
    • , Xiaofeng Fang
    •  & Minbiao Ji
  • Article
    | Open Access

    Uniform illumination is a prerequisite for quantitative analyses in both classical fluorescence microscopy and single molecule localisation microscopy. Here, the authors introduce ASTER, an illumination technique that generates uniform illumination over large and adaptable fields of view, compatible with epifluorescence, HiLo and TIRF illumination schemes.

    • Adrien Mau
    • , Karoline Friedl
    •  & Sandrine Lévêque-Fort
  • Article
    | Open Access

    Diffractive optical elements are broadly used due to their ability to reshape the wavefront efficiently and conveniently. By using liquid immersion, the authors here enable microscale 3D-printed optics to behave like nanoscopic structures while maintaining high performance.

    • Reut Orange-Kedem
    • , Elias Nehme
    •  & Yoav Shechtman
  • Article
    | Open Access

    Raman optical activity (ROA) is useful for studying conformational structure and behavior of chiral molecules, but is limited by the weak signals. Here, the authors demonstrate 100x signal enhancement via an all-dielectric approach, using a silicon nanodisk array and exploiting its dark mode.

    • Ting-Hui Xiao
    • , Zhenzhou Cheng
    •  & Keisuke Goda
  • Article
    | Open Access

    Here, the authors present a high-speed photothermal spatial light modulator which can generate a step-like wavefront change without diffraction artifacts. They use this to perform quantitative phase imaging, capturing sub-millisecond motion with a nanometer resolution in 3D.

    • Hadrien M. L. Robert
    • , Kristýna Holanová
    •  & Marek Piliarik
  • Article
    | Open Access

    The famous Kramers turnover describes the extent of friction at which the transition rate of a small particle trapped in a bistable potential becomes a maximum. Militaru et al. present a version of this phenomenon pertaining to active colloids driven by non-conservative forces.

    • A. Militaru
    • , M. Innerbichler
    •  & C. Dellago
  • Article
    | Open Access

    Transparent photodetectors based on graphene stacked vertically along the optical axis have shown promising potential for light field reconstruction. Here, the authors develop transparent photodetector arrays and implement a neural network for real-time 3D optical imaging and object tracking.

    • Dehui Zhang
    • , Zhen Xu
    •  & Theodore B. Norris
  • Article
    | Open Access

    Extracting weak, ultrafast single-shot waveforms from a noisy background has critical uses in many applications. Here, the authors present a method to enhance signals and recover arbitrary waveforms from very noisy backgrounds by manipulating the physical waveform spectra in real time.

    • Benjamin Crockett
    • , Luis Romero Cortés
    •  & José Azaña
  • Article
    | Open Access

    Encoding data in DNA is a promising approach to high density data storage. Here the authors present a prototype sequencing-free method that uses the spatial orientation of DNA strands with super-resolution microscopy readout.

    • George D. Dickinson
    • , Golam Md Mortuza
    •  & William L. Hughes