Research articles

Filter By:

Article Type
Year
  • A parallel implementation of multifocal multiphoton modulation microscopy allows simultaneous phosphorescent lifetime and intensity imaging in vivo at speeds 100 times faster than conventional configurations. Three-dimensional imaging of a phosphorescent quenching dye is also presented.

    • Scott S. Howard
    • Adam Straub
    • Chris Xu
    Letter
  • Researchers report the entanglement-enhanced measurement of a delicate material system, in which they non-destructively probe an 85Rb atomic spin ensemble by near-resonant Faraday rotation. They use narrowband, atom-resonant ‘NOON’ states to beat the standard quantum limit of sensitivity by more than five standard deviations, both on a per-photon and a per-damage basis.

    • Florian Wolfgramm
    • Chiara Vitelli
    • Morgan W. Mitchell
    Letter
  • Researchers focus 10 keV X-ray free-electron laser radiation to an area of 0.95 µm × 1.20 µm with near-100%-efficiency using reflective optics. This approach increases the fluence by a factor of 40,000 and provides a power density of 6 × 1017 W cm−2.

    • Hirokatsu Yumoto
    • Hidekazu Mimura
    • Kazuto Yamauchi
    Letter
  • Scientists report that the photovoltaic effect and a photo-induced bolometric effect, rather than thermoelectric effects, dominate the photoresponse during a classic photoconductivity experiment in biased graphene. The findings shed light on the hot-electron-driven photoresponse in graphene and its energy loss pathway via phonons.

    • Marcus Freitag
    • Tony Low
    • Phaedon Avouris
    Article
  • Researchers demonstrate that Bell's measure — a commonly used test of quantum nonlocality — can be used in classical optical schemes to separate incoherence associated with statistical fluctuations from incoherence based on correlation. This technique may be useful for quantum information applications such as classical optical coherence theory and optical signal processing.

    • Kumel H. Kagalwala
    • Giovanni Di Giuseppe
    • Bahaa E. A. Saleh
    Article
  • Magnetic effects are fundamentally weak at optical frequencies. Now, by applying inhomogeneous strain in photonic band structures of a honeycomb lattice of waveguides, scientists show experimentally and theoretically that it is possible to induce a pseudomagnetic field at optical frequencies. The field yields 'photonic Landau levels', which suggests the possibility of achieving greater field enhancements and slow-light effects in aperiodic photonic crystal structures than those available in periodic structures.

    • Mikael C. Rechtsman
    • Julia M. Zeuner
    • Alexander Szameit
    Article
  • Random lasing in the presence of nonlinearities and disordered gain media is still poorly understood. Researchers now present a semiclassical theory for multimode random lasing in the strongly scattering regime. They show that Anderson localization — a wave-interference effect — is not affected by the presence of nonlinearities, but instead suppresses interactions between simultaneously lasing modes.

    • Peter Stano
    • Philippe Jacquod
    Article
  • Researchers demonstrate large cross-phase shifts of 0.3 mrad per photon in a single pass through room-temperature Rb atoms confined to a hollow-core photonic bandgap fibre. The response time of less than 5 ns indicates that phase modulation bandwidths greater than 50 MHz are possible with a highly sensitive atomic-vapour-based scheme.

    • Vivek Venkataraman
    • Kasturi Saha
    • Alexander L. Gaeta
    Letter
  • Coherent control is a powerful tool for controlling light–matter interactions in time and frequency. Now, scientists show that counter-propagating broadband pulses can be used to generate fully controlled spatial excitation patterns. This spatial control approach also reduces decoherence, providing a high-frequency resolution similar to that of an optical frequency comb.

    • Itan Barmes
    • Stefan Witte
    • Kjeld S. E. Eikema
    Letter
  • Scientists demonstrate a simple approach for separating a nonlinearly generated attosecond pulse train into multiple beams of isolated attosecond pulses that propagate in different and controlled directions away from the plasma surface. The approach involves rotating the propagation direction of an intense few-cycle laser field as it interacts with a solid-density plasma.

    • Jonathan A. Wheeler
    • Antonin Borot
    • Fabien Quéré
    Letter
  • Chaotic behaviour is observed in the polarization of the output from a vertical-cavity surface emitting laser without the need for any external stimulus or feedback. The origin is nonlinear coupling between two elliptically polarized modes within the device.

    • Martin Virte
    • Krassimir Panajotov
    • Marc Sciamanna
    Article
  • Researchers optically control an active medium. Strong light-matter interaction causes superdiffusion that is controllable by the input optical power. The idea may be applied to exploring nonequilibrium thermodynamics of soft-matter or enable new possibilities for the coherent control of strongly coupled, complex systems.

    • Kyle M. Douglass
    • Sergey Sukhov
    • Aristide Dogariu
    Letter
  • Researchers use single-cycle THz pulses from an optical laser to extend streaking techniques of attosecond metrology to measure the temporal profile and arrival time of individual FEL pulses with ∼5 fs precision.

    • I. Grguraš
    • A. R. Maier
    • A. L. Cavalieri
    Article
  • Video-rate imaging of various types of biological tissue is reported using stimulated Raman scattering microscopy. The label-free scheme offers molecular specificity and frame-by-frame wavelength tunability allowing the creation of 2D and 3D images of samples showing different constituents.

    • Yasuyuki Ozeki
    • Wataru Umemura
    • Kazuyoshi Itoh
    Article
  • A photoelectrochemical cell made from combining a dye sensitized solar cell with a semiconductor-oxide photoanode is demonstrated to perform water splitting with an efficiency of up to 3.1%. As the scheme uses relatively inexpensive materials and fabrication techniques it could provide a cost effective approach to hydrogen production.

    • Jeremie Brillet
    • Jun-Ho Yum
    • Kevin Sivula
    Letter
  • Researchers bring together silk and photonic crystals and report the manufacturing of robust, freestanding, three-dimensional photonic crystals with different lattice constants in the structural form of an inverse opal entirely composed of silk fibroin. These silk-based inverse opals add a new dimension at the interface of nanophotonics and biological applications.

    • Sunghwan Kim
    • Alexander N. Mitropoulos
    • Fiorenzo G. Omenetto
    Letter
  • Researchers create high ionization states, up to Xe36+, using 1.5 keV free-electron laser pulses. The higher than expected ionization may be due to transient resonance-enhanced absorption and the effect may play an important role in interactions of intense X-rays with high-Z elements and radiation damage.

    • Benedikt Rudek
    • Sang-Kil Son
    • Daniel Rolles
    Article