Volume 7 Issue 10, October 2013

A pulling force can be generated via amplification of the photon linear momentum when a fairly uniform light field passes from one dielectric to another with a higher refractive index. This force can drag small objects over macroscopic distances along dielectric interfaces.

Researchers show that the breakdown of temporal coherence in a fibre laser has strong similarities with the onset of turbulence in fluids. Establishing a conceptual connection between these different systems can offer new perspectives for both fields.

Flexible electronics and optoelectronics have potential applications in energy generation, biomedicine, robotics and displays. Two recent demonstrations of highly stretchable polymer LEDs suggest that commercial devices may soon become viable.

Vertically aligned nanowires on a solid surface in conjunction with table-top lasers create an ultrahigh-energy-density plasma with extremely high ionization in the laboratory.

Inertial fusion energy is one potential path towards realizing sustainable energy. The development of a laser power plant capable of delivering high-energy laser pulses is crucial for realizing laser-driven inertial fusion energy.

Laser-driven plasma accelerators have the potential to replace existing particle accelerators, as they are highly efficient systems that are orders of magnitude smaller than conventional particle accelerators. This review discusses recent progress and future challenges in this area.

The transition between operation in a stable coherent state and that in a disordered turbulent state is studied in a fibre laser. The loss of coherence following the transition is associated with the appearance of solitons, which proliferate and cluster.

Gradientless light fields are shown to exert pulling forces on arbitrary objects in purely passive dielectric media. These forces arise from amplification of the photon linear momentum when light is scattered from one dielectric to another with a higher refractive index. They can manipulate objects over macroscopic distances along dielectric interfaces.

Previously demonstrated zero- or negative-refractive-index metamaterials at optical frequencies suffer from large ohmic losses because of the need to use metals. Metamaterials formed by stacked silicon rod unit cells allow the realization of all-dielectric impedance-matched zero-index metamaterials operating at optical frequencies, potentially benefiting the development of angular-selective optical devices.

Femtosecond laser pulses were used to heat dense matter, converting it into an extremely hot plasma. 52-times ionized gold was achieved as well as gigabar pressures, which can be exceeded only in the central hot spots of thermonuclear fusion plasmas.

A chip-compatible beamsplitter that can separate left- and right-handed circularly polarized light is promising for constructing more sophisticated integrated optical circuits. The prism-shaped device, which operates around the telecommunication wavelength of 1.5 μm, consists of a photonic crystal composed of an array of helical structures.

A confocal fluorescence microscopy scheme that maps the image to the radiofrequency spectrum by beating together two optical fields offers enhanced read-out speeds at kilohertz frame rates. It provides a new way for observing dynamic phenomena in cells.

Ultrathin sheets of polymer LEDs that emit light even when being crumpled or stretched have been realized. The 2-μm-thick devices emit red or orange light with a sufficiently high brightness for indoor applications, and they could prove useful for integration with textiles.

A stretchable polymer LED is fabricated that is capable of emitting light when subjected to strains as large as 120%. A prototype 5 × 5 pixel monochrome display based on an array of these LEDs is demonstrated.

New designs of donor polymers yield organic solar cells with fill factors approaching 80%, significantly higher than those of conventional cells. This enhanced performance is attributed to the close-packed and highly ordered structure of the polymers PTPD3T and PBT13T, which leads to efficient charge extraction and suppressed recombination.

The long-standing problem of determining the classical communication capacities of Gaussian bosonic channels is addressed by determining upper and lower bounds for the classical capacities of important active and passive bosonic channels. The results apply to any bosonic thermal-noise channel, including electromagnetic signaling at any frequency.

Clustering of dark and grey solitons in fibre lasers has been found to induce a turbulent regime similar to that of a rapidly flowing fluid in a pipe. Sergei Turitsyn from the University of Aston, UK, explains.