Optics and photonics

  • Article
    | Open Access

    Resonators are key components in optics. In this work, the authors introduce a class of optical resonators with distinctly different properties from conventional resonators, allowing fundamental design trade-offs to be circumvented.

    • Vincent Ginis
    • , Ileana-Cristina Benea-Chelmus
    •  & Federico Capasso
  • Article
    | Open Access

    Designing efficient photonic neuromorphic systems remains a challenge. Here, the authors develop an in-sensor Reservoir Computing system for multi-tasked pattern classification based on a light-responsive semiconducting polymer (p-NDI) with efficient exciton dissociations, charge trapping capability, and through-space charge-transport characteristics.

    • Xiaosong Wu
    • , Shaocong Wang
    •  & Weiguo Huang
  • Article
    | Open Access

    Generation and control of short pulse is desired for ultrafast applications. Here the authors demonstrate ultrafast pulse generation using self-evolving photonic crystal that can transition from high loss to low loss state based on dynamic dispersion compensation.

    • Takuya Inoue
    • , Ryohei Morita
    •  & Susumu Noda
  • Article
    | Open Access

    A suppressed energy loss through Dexter energy transfer is crucial to achieve highly efficient blue organic light-emitting diodes. Here, authors synthesize quadrupolar donor-acceptor-donor type thermally activated delayed fluorescence sensitizers and realize device with maximum efficiency of 43.9%.

    • Hyuna Lee
    • , Ramanaskanda Braveenth
    •  & Jang Hyuk Kwon
  • Article
    | Open Access

    Luminophores based on clustering-triggered emission have drawn emerging attention in recent years but they tend to be nonluminescent in dilute solution. Here, the authors design novel clusteroluminogens through modification of cyclodextrin (CD) with amino acids to enable clusterization of chromophores in CD-based confined space and realize blue to cyan fluorescence even in the dilute solution.

    • Qiuju Li
    • , Xingyi Wang
    •  & Shun Mao
  • Article
    | Open Access

    Quasi-2D halide perovskites are attracting increasing attention for light-emitting devices. Here, the authors demonstrated efficient and stable quasi-2D perovskite LEDs enabled by suppressed phase disproportionation with newly designed organic ligands.

    • Kang Wang
    • , Zih-Yu Lin
    •  & Letian Dou
  • 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

    The origin of the Rayleigh–Jeans distribution associated with light thermalization in optical thermodynamic multimode nonlinear settings is discussed. Here the authors show that due to entropy maximization, this process is universal and is independent of the intricacies of the nonlinearities involved.

    • Qi Zhong
    • , Fan O. Wu
    •  & Demetrios N. Christodoulides
  • Article
    | Open Access

    Quantum random number generators should ideally rely on few assumptions, have high enough generation rates, and be cost-effective and easy to operate. Here, the authors show an untrusted-homodyne-based MDI scheme that does not rely on i.i.d. assumption and is secure against quantum side information.

    • Chao Wang
    • , Ignatius William Primaatmaja
    •  & Charles Lim
  • Article
    | Open Access

    The surface localized charges in colloidal quantum dots induce a degradation that limits the electroluminescence performance. Here, Chen et al. propose quantum dots with monmonotonically-graded core/shell/shell structures to boost the device’s performance by reducing the surface-bulk coupling.

    • Xingtong Chen
    • , Xiongfeng Lin
    •  & Song Chen
  • Article
    | Open Access

    Flexible and coherent light generation is of paramount importance to enable new functionalities in integrated silicon photonics. Here the authors, develop an optical parametric oscillator with high conversion efficiency and high output power, based on the third order nonlinearity in a silicon nitride microresonator

    • Edgar F. Perez
    • , Grégory Moille
    •  & Kartik Srinivasan
  • Article
    | Open Access

    Studies on the fractional Schrödinger equation (FSE) remain mostly theoretical, due to the lack of materials supporting fractional dispersion or diffraction. Here, the authors indirectly realized the FSE using two programmable holograms acting as an optical Lévy waveguide.

    • Shilong Liu
    • , Yingwen Zhang
    •  & Ebrahim Karimi
  • Article
    | Open Access

    Microcombs are vulnerable to the environmental perturbations. Here, the authors propose a universal mechanism to fully control the microcombs. Based this reconfigurable microsoliton, a wavemeter with a precision of kHz is demonstrated.

    • Rui Niu
    • , Ming Li
    •  & Chun-Hua Dong
  • Article
    | Open Access

    Frequency-bin qubits get the best of time-bin and dual-rail encodings, but require external modulators and pulse shapers to build arbitrary states. Here, instead, the authors work directly on-chip by controlling the interference of biphoton amplitudes generated in multiple, coherently-pumped ring resonators.

    • Marco Clementi
    • , Federico Andrea Sabattoli
    •  & Daniele Bajoni
  • 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

    Optical neural networks face remarkable challenges in high-level integration and on-chip operation. In this work the authors enable optical convolution utilizing time-wavelength plane stretching approach on a microcomb-driven chip-based photonic processing unit.

    • Bowen Bai
    • , Qipeng Yang
    •  & Xingjun Wang
  • Article
    | Open Access

    Integrating diffractive optical neural networks (DONN) would reduce errors due to bulky components and calibration. Here, the authors exploit integrated 1D dielectric metasurfaces to realise an on-chip DONN device with 90% classification accuracy, computing at 10^16 flops/mm^2 and consuming 10E-17 J/Flop.

    • Tingzhao Fu
    • , Yubin Zang
    •  & Hongwei Chen
  • Article
    | Open Access

    Convolutional operation is a very efficient way to handle tensor analytics, but it consumes a large quantity of additional memory. Here, the authors demonstrate an integrated photonic tensor processor which directly handles high-order tensors without tensor-matrix transformation.

    • Shaofu Xu
    • , Jing Wang
    •  & Weiwen Zou
  • Article
    | Open Access

    Traditional learning procedures for artificial intelligence rely on digital methods not suitable for physical hardware. Here, Nakajima et al. demonstrate gradient-free physical deep learning by augmenting a biologically inspired algorithm, accelerating the computation speed on optoelectronic hardware.

    • Mitsumasa Nakajima
    • , Katsuma Inoue
    •  & Kohei Nakajima
  • 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

    The authors present an approach to phase imaging by using the non-local optical response of a guided-moderesonator metasurface. They demonstrate that this metasurface can be added to a conventional microscope to enable quantitative phase contrast imaging.

    • Anqi Ji
    • , Jung-Hwan Song
    •  & Mark L. Brongersma
  • 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

    The exciton Mott transition refers to a transition from an insulating state of gas-like excitons to strongly correlated electron-hole plasma phases in photoexcited semiconductors. Here the authors experimentally study such a transition in black phosphorus and reveal its quantum critical properties.

    • Binjie Zheng
    • , Junzhuan Wang
    •  & Xiaomu Wang
  • 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

    Light penetration and overheating are major issues facing the application of photothermal therapy. Here, the authors develop a temperature responsive hydrogel optical waveguide for controlled delivery of light to deep tumours and demonstrate biocompatibility and temperature responsive phototherapy in vivo

    • Guoyin Chen
    • , Kai Hou
    •  & Meifang Zhu
  • 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

    There are many possible mechanisms of high-harmonic generation from crystals. Here the authors discuss the role of the Bloch oscillation to nonlinear response of the crystal and harmonic radiation from it.

    • Jan Reislöhner
    • , Doyeong Kim
    •  & Adrian N. Pfeiffer
  • Article
    | Open Access

    Here, the authors predict that plasmons in two-dimensional materials with closely located electron and hole Fermi pockets can be amplified when an electrical current bias is applied along the displaced electron-hole pockets, without the need for an external gain medium.

    • Sang Hyun Park
    • , Michael Sammon
    •  & Tony Low
  • Article
    | Open Access

    The recently demonstrated approaches to fabrication of quantum emitters in silicon result in their random positioning, hindering applications in quantum photonic integrated circuits. Here the authors demonstrate controlled fabrication of telecom-wavelength quantum emitters in silicon wafers by focused ion beams.

    • Michael Hollenbach
    • , Nico Klingner
    •  & Georgy V. Astakhov
  • Article
    | Open Access

    Applications of ultra-low-loss photonic circuitry in quantum photonics, in particular including triggered single photon sources, are rare. Here, the authors show how InAs quantum dot single photon sources can be integrated onto wafer-scale, CMOS compatible ultra-low loss silicon nitride photonic circuits.

    • Ashish Chanana
    • , Hugo Larocque
    •  & Marcelo Davanco