Optical techniques

  • Article
    | Open Access

    Complex molecules show element- and enantio-specific properties and reactivity. Here the authors demonstrate identification of the element- and enantiomer-selective motion of Ibuprofen molecule using X-ray photons at the carbon K-edge.

    • R. Mincigrucci
    • , J. R. Rouxel
    •  & C. Masciovecchio
  • Article
    | Open Access

    Diagnosis of bile duct cancer often occur in advanced stages, leading to poor survival. Here, the authors combine light scattering and diffuse reflectance spectroscopies in a minimally invasive endoscopic technique for directly assessing the malignant potential of the bile duct lining, and demonstrate 97% detection accuracy.

    • Douglas K. Pleskow
    • , Mandeep S. Sawhney
    •  & Lev T. Perelman
  • Article
    | Open Access

    The authors investigate whether strong light-matter coupling can alter the nonlinear optical response of molecules inside a microcavity. Focusing on electroabsorption as a model third order nonlinearity, they find that apparent discrepancies between experiment and classical transfer matrix modeling arise from dark states in the system and are not a sign of new physics in the strong coupling regime.

    • Chiao-Yu Cheng
    • , Nina Krainova
    •  & Noel C. Giebink
  • Article
    | Open Access

    The authors present single-pixel imaging accelerated via swept aggregate patterns (SPI-ASAP), which combines a digital micromirror device with laser scanning for fast and reconfigurable pattern projection, and a lightweight reconstruction algorithm. They demonstrate real-time video streaming at 100 fps, and up to 12,000 fps offline.

    • Patrick Kilcullen
    • , Tsuneyuki Ozaki
    •  & Jinyang Liang
  • Article
    | Open Access

    The authors present a single-shot 3D imaging approach utilizing carefully designed point clouds projection based on a metasurface device. They show submillimeter depth accuracy and demonstrate the potential for hand gesture detection.

    • Xiaoli Jing
    • , Ruizhe Zhao
    •  & Lingling Huang
  • Article
    | Open Access

    Structured Illumination Microscopy allows for the visualization of biological structures at resolutions below the diffraction limit, but this imaging modality is still hampered by high experimental complexity. Here, the authors present a combination of interferometry and machine learning to construct a structured illumination microscope for super resolution imaging of dynamic sub-cellular biological structures in multiple colors.

    • Edward N. Ward
    • , Lisa Hecker
    •  & Clemens F. Kaminski
  • Article
    | Open Access

    It is currently debated how to reliably distinguish liquid–liquid phase separation (LLPS) from other mechanisms. Here the authors report model-free calibrated half-FRAP (MOCHA-FRAP) to probe the barrier at the condensate interface that is responsible for preferential internal mixing in LLPS.

    • Fernando Muzzopappa
    • , Johan Hummert
    •  & Fabian Erdel
  • Article
    | Open Access

    The authors introduce Bond-selective Intensity Diffraction Tomography, a computational mid-infrared photothermal microscopy technique based on a standard bright-field microscope and an add-on pulsed light source. It recovers both mid-infrared spectra and bond-selective 3D refractive index maps based on intensity-only measurements.

    • Jian Zhao
    • , Alex Matlock
    •  & Ji-Xin Cheng
  • Article
    | Open Access

    Super-resolution microscopy techniques can be challenging for live cells and thick samples. Here, the authors propose a method to reduce beam intensity and remove out-of-focus fluorescence background in image-scanning microscopy (ISM) and its combination with stimulated emission depletion (STED).

    • Giorgio Tortarolo
    • , Alessandro Zunino
    •  & Giuseppe Vicidomini
  • Article
    | Open Access

    Traditional methods for cell stiffness measurements are limited by long processing times and unsuitability for multiple cell analysis. Here, the authors demonstrate a fast technique based on acoustic stimulation and holographic imaging to reconstruct whole-cell stiffness maps of individual and multiple cells.

    • Rahmetullah Varol
    • , Zeynep Karavelioglu
    •  & Huseyin Uvet
  • Article
    | Open Access

    Holography recreates both the amplitude and wave front of a three dimensional object, meaning that the observer perceives the image in the nearly same way as they would the true object. Creating such holographic images is challenging computationally, and requires extremely fast display update. Here, the authors combine a fast memoryless computation algorithm with the ultra-rapid writing based on all-optical switching of a ferrimagnetic film.

    • M. Makowski
    • , J. Bomba
    •  & A. Stupakiewicz
  • Article
    | Open Access

    Experimental evidence is given that upon the optical excitation of surface plasmon polaritons, a nonthermal electron population appears in the topmost domain of the plasmonic film directly coupled to the local fields.

    • Judit Budai
    • , Zsuzsanna Pápa
    •  & Péter Dombi
  • Article
    | Open Access

    The authors report high-efficiency emission depletion through a surface migration emission depletion mechanism, which takes advantage of the effects of surface quenching and energy migration in nanocrystals. They demonstrate super-resolution microscopy with very low depletion saturation intensities.

    • Rui Pu
    • , Qiuqiang Zhan
    •  & Xiaogang Liu
  • Article
    | Open Access

    The authors demonstrate a label-free superresolution imaging method by using a hyperbolic material as a substrate for tailored light-matter interactions. The hyperbolic material enhanced scattering, combined with dark-field detection, result in 5.5-fold resolution improvement beyond the diffraction limit.

    • Yeon Ui Lee
    • , Shilong Li
    •  & Zhaowei Liu
  • Article
    | Open Access

    The optoelectronic performance of lead halide perovskite in highfluence applications are hindered by heterogeneous multi-polaron interactions in the nanoscale. Here, Nishda et al. spatially resolve sub-ns relaxation dynamics on the nanometer scale by ultrafast infrared pumpprobe nanoimaging.

    • Jun Nishida
    • , Peter T. S. Chang
    •  & Markus B. Raschke
  • Article
    | Open Access

    Designing and manufacturing eco/bioresorbable electronic systems remains a challenge. The authors introduce a picosecond-pulsed laser-based scheme that exploits controlled patterning, thinning, and/or cutting to manipulate multilayers of eco/bioresorbable materials for a wide range of advanced electronic systems.

    • Quansan Yang
    • , Ziying Hu
    •  & John A. Rogers
  • Article
    | Open Access

    The authors developed a pristine hyperspectral SPR microscopy that enables monochromatic and polychromatic SPR imaging with flexible field-of-view option, single-pixel spectral SPR sensing and 2D quantification of thin films with resonant wavelength images.

    • Ziwei Liu
    • , Jingning Wu
    •  & Zhi-mei Qi
  • Article
    | Open Access

    Energy transfer between the electromagnetic field and atoms or molecules is fundamentally interesting. Here the authors demonstrate stepwise energy transfer between broadband mid-infrared optical pulses and vibrating methylsulfonylmethane molecules in aqueous solution.

    • Martin T. Peschel
    • , Maximilian Högner
    •  & Ioachim Pupeza
  • Article
    | Open Access

    Imaging though strongly scattering media is challenging and computationally intensive. Here, the authors show that tracking of moving objects can be achieved with minimal computational effort by combining cross-correlations of the measured speckle pattern at different times.

    • Y. Jauregui-Sánchez
    • , H. Penketh
    •  & J. Bertolotti
  • Article
    | Open Access

    Mimicking human vision with metasurfaces, the authors propose a new paradigm for high field of view and ultrafast LiDAR, achieving performances also relevant for the next generation of imaging system for ADAS and robotic systems.

    • Renato Juliano Martins
    • , Emil Marinov
    •  & Patrice Genevet
  • Article
    | Open Access

    Sensitivity to noise is currently an obstacle to the use of quantum imaging techniques in real-world scenarios. Here, exploiting non-local cancellation of dispersion on time-frequency entangled photons, the authors show a 43dB improvement in resilience to noise for imaging protocols towards a quantum LiDAR.

    • Phillip S. Blakey
    • , Han Liu
    •  & Amr S. Helmy
  • Article
    | Open Access

    The defocusing problem has been considered the main bottleneck for developing optoelectronic μ-compound eye (CE) cameras. Here, the authors report miniature optoelectronic CE cameras with an ommatidia logarithmic-profile. The camera enables large field-of-view imaging, spatial position identification, and sensitive trajectory monitoring of moving targets.

    • Zhi-Yong Hu
    • , Yong-Lai Zhang
    •  & Hong-Bo Sun
  • Article
    | Open Access

    The authors present an approach to underwater imaging, which does not require tethering or batteries. The low-power camera uses power from harvested acoustic energy and communicates colour images wirelessly via acoustic backscatter.

    • Sayed Saad Afzal
    • , Waleed Akbar
    •  & Fadel Adib
  • Article
    | Open Access

    Estimating the angular separation between two incoherent sources below the diffraction limit is challenging. Hypothesis testing and quantum state discrimination techniques are used to super-resolve sources of different brightness with a simple optical interferometer.

    • Ugo Zanforlin
    • , Cosmo Lupo
    •  & Zixin Huang
  • Article
    | Open Access

    Studying microorganisms at high temperatures is challenging on conventional optical microscopes. Here, the authors introduce the concept of microscale laser heating over the full field of view by using gold nanoparticles as light absorbers, and study thermophile species up to 80 °C.

    • Céline Molinaro
    • , Maëlle Bénéfice
    •  & Guillaume Baffou
  • Article
    | Open Access

    Optical binding enables light-induced assembly of many particles within a focus area. Here, the authors demonstrate that optical binding can occur outside the irradiated area by scattered light interacting with the particles outside the focus, generating arc-shape potential wells for particle trapping.

    • Chih-Hao Huang
    • , Boris Louis
    •  & Hiroshi Masuhara
  • Article
    | Open Access

    Laser probing of integrated circuits using sub-bandgap photon energies remains a challenge. Here, the authors propose a super-resolution method capable of achieving probe placement accuracy to better than 10 nm; extraction of electro-optic waveforms from a node of a group of transistors and applied this to isolate and identify a fault on a defective device.

    • V. K. Ravikumar
    • , Jiann Min Chin
    •  & Joel K. W. Yang
  • Article
    | Open Access

    Light sheet microscopes reduce phototoxicity and background while improving imaging speed compared to widefield and confocal microscopes. Here the authors quantify the differences between Gaussian and lattice light sheets using simulations and experimental data in fixed and live cells.

    • Yu Shi
    • , Timothy A. Daugird
    •  & Wesley R. Legant
  • Article
    | Open Access

    Nanoscale emitters are useful for measuring biomolecular interactions, but are limited by weak signals. Here, the authors use a photonic crystal surface for 3000-fold signal enhancement, achieving single emitter sensitivity with extended on-time, and demonstrate its application in miRNA biomarker sensing.

    • Yanyu Xiong
    • , Qinglan Huang
    •  & Brian T. Cunningham
  • Article
    | Open Access

    There is a need to control molecular activities at high spatial precision. Here the authors report a real-time precision opto-control technology that detects a chemical-specific optical response from molecular targets, and precisely control photoswitchable microtubule polymerization inhibitors in cells.

    • Matthew G. Clark
    • , Gil A. Gonzalez
    •  & Chi Zhang
  • Article
    | Open Access

    Here, the authors develop a UV-compatible photonic integrated circuit for structured illumination microscopy on a conventional wide-field microscope. Operating at a wavelength of 360 nm, they generate switchable far-field fringe patterns, and demonstrate autofluorescence imaging of yeast cells.

    • Chupao Lin
    • , Juan Santo Domingo Peñaranda
    •  & Nicolas Le Thomas
  • Article
    | Open Access

    The authors fabricate a 3D achromatic diffractive metalens on the end face of a single-mode fiber, useful for endoscopic applications. They demonstrate achromatic and polarization insensitive focusing across the entire near-infrared telecommunication wavelength band ranging from 1.25 to 1.65 µm.

    • Haoran Ren
    • , Jaehyuck Jang
    •  & Stefan A. Maier
  • Article
    | Open Access

    Infrared spectroscopy with plasmonic nanoantennas is limited by small overlap between molecules and hot spots, and sharp resonance peaks. The authors demonstrate spectral multiplexing of hook nanoantennas with gradient dimensions as ultrasensitive vibrational probes in a continuous ultra-broadband region and utilize machine learning for enhanced sensing performance.

    • Zhihao Ren
    • , Zixuan Zhang
    •  & Chengkuo Lee