Author(s): Seng Fatt Liew and Hui Cao

Enhancing light transmission through scattering media is of much interest in many fields. Here, numerical simulations are performed to study the impact of gain on the value of reflection of the minimum reflection channel in a random medium. Surprisingly, in some random configurations, the reflection falls when gain is added even through the intensity inside the medium presumably increases once gain is introduced. This unexpected behavior is explained based on a decomposition of quasinormal modes.

[Phys. Rev. B 92, 224202] Published Tue Dec 29, 2015

Single-chip microprocessor that communicates directly using light

Nature 528, 7583 (2015). doi:10.1038/nature16454

Authors: Chen Sun, Mark T. Wade, Yunsup Lee, Jason S. Orcutt, Luca Alloatti, Michael S. Georgas, Andrew S. Waterman, Jeffrey M. Shainline, Rimas R. Avizienis, Sen Lin, Benjamin R. Moss, Rajesh Kumar, Fabio Pavanello, Amir H. Atabaki, Henry M. Cook, Albert J. Ou, Jonathan C. Leu, Yu-Hsin Chen, Krste Asanović, Rajeev J. Ram, Miloš A. Popović & Vladimir M. Stojanović

Data transport across short electrical wires is limited by both bandwidth and power density, which creates a performance bottleneck for semiconductor microchips in modern computer systems—from mobile phones to large-scale data centres. These limitations can be overcome by using optical communications based on chip-scale electronic–photonic systems enabled by silicon-based nanophotonic devices8. However, combining electronics and photonics on the same chip has proved challenging, owing to microchip manufacturing conflicts between electronics and photonics. Consequently, current electronic–photonic chips are limited to niche manufacturing processes and include only a few optical devices alongside simple circuits. Here we report an electronic–photonic system on a single chip integrating over 70 million transistors and 850 photonic components that work together to provide logic, memory, and interconnect functions. This system is a realization of a microprocessor that uses on-chip photonic devices to directly communicate with other chips using light. To integrate electronics and photonics at the scale of a microprocessor chip, we adopt a ‘zero-change’ approach to the integration of photonics. Instead of developing a custom process to enable the fabrication of photonics, which would complicate or eliminate the possibility of integration with state-of-the-art transistors at large scale and at high yield, we design optical devices using a standard microelectronics foundry process that is used for modern microprocessors. This demonstration could represent the beginning of an era of chip-scale electronic–photonic systems with the potential to transform computing system architectures, enabling more powerful computers, from network infrastructure to data centres and supercomputers.

Author(s): Behzad Khanaliloo, Harishankar Jayakumar, Aaron C. Hryciw, David P. Lake, Hamidreza Kaviani, and Paul E. Barclay

Optomechanics, which refers to the interplay of light and nanomechanics, has widespread applications in sensing and quantum optics. Researchers demonstrate that an optomechanical system based on single-crystal diamond nanobeams can undergo large self-oscillations.

[Phys. Rev. X 5, 041051] Published Tue Dec 29, 2015

Author(s): Matthew R. Foreman, Alberto Favaro, and Andrea Aiello

Complete determination of the polarization state of light requires at least four distinct projective measurements of the associated Stokes vector. Stability of state reconstruction, however, hinges on the condition number κ of the corresponding instrument matrix. Optimization of redundant measuremen…

[Phys. Rev. Lett. 115, 263901] Published Wed Dec 23, 2015

An analysis of London’s street network shows how the network has evolved over time from a heterogeneous to homogeneous fractal pattern.

[Physics] Published Thu Dec 17, 2015

We develop an analytic circuit model for coupled plasmonic dimers separated by small gaps that provides a complete account of the optical resonance wavelength. Using a suitable equivalent circuit, it shows how partially conducting links can be treated and provides quantitative agreement with both experiment and full electromagnetic simulations. The model highlights how in the conducting regime, the kinetic inductance of the linkers set the spectral blue-shifts of the coupled plasmon.

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Article

Plasmons can enhance hot-carrier generation for efficient photochemical reactions, but the interplay between plasmons and single-particle excitations are difficult to capture in models. Here, the authors use real-time time-dependent density functional theory to study these interactions in silver nanocrystals.

Nature Communications doi: 10.1038/ncomms10107

Authors: Jie Ma, Zhi Wang, Lin-Wang Wang

We present a quantum theoretical treatment of light-matter coupling in the system consisting of a quantum dot and a spherical core-shell metal-dielectric multilayer nanoparticle. It is shown that both weak and strong coupling regimes can be realized in the set-up. Specifically, we demonstrate a strong coupling regime between a quantum dot and a nanoparticle, when the quantum dot resonance is tuned to the frequency at which normal component of effective nanoparticle permittivity is crossing zero. Moreover, we demonstrate the regime at which the quantum dot decays much faster than in vacuum (due to the large Purcell factor) and at the same time radiates more power to the far field. This findings pave the way towards more efficient control over radiation properties of quantum emitters.

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Author(s): Tanya Das, Prasad P. Iyer, Ryan A. DeCrescent, and Jon A. Schuller

The ability to control multipolar light-matter interactions in metamaterials and other photonic systems has traditionally relied on engineering the physical properties of the resonators. In this paper, the authors follow the reverse approach. By tailoring the optical beam that illuminates a spherical nanoparticle, they demonstrate selective and enhanced coupling to the optical modes excited on the nanoparticle.

[Phys. Rev. B 92, 241110(R)] Published Mon Dec 14, 2015

Author(s): Scott A. Skirlo, Ling Lu, Yuichi Igarashi, Qinghui Yan, John Joannopoulos, and Marin Soljačić

A two-dimensional photonic crystal has multiple topologically protected channels, which can be used to transmit and reroute light without scattering losses.

[Phys. Rev. Lett. 115, 253901] Published Mon Dec 14, 2015

Author(s): Marissa Giustina, Marijn A. M. Versteegh, Sören Wengerowsky, Johannes Handsteiner, Armin Hochrainer, Kevin Phelan, Fabian Steinlechner, Johannes Kofler, Jan-Åke Larsson, Carlos Abellán, Waldimar Amaya, Valerio Pruneri, Morgan W. Mitchell, Jörn Beyer, Thomas Gerrits, Adriana E. Lita, Lynden K. Shalm, Sae Woo Nam, Thomas Scheidl, Rupert Ursin, Bernhard Wittmann, and Anton Zeilinger

By closing two loopholes at once, three experimental tests of Bell’s inequalities remove the last doubts that we should renounce local realism. They also open the door to new quantum information technologies.

[Phys. Rev. Lett. 115, 250401] Published Wed Dec 16, 2015

Author(s): Carlos Abellán, Waldimar Amaya, Daniel Mitrani, Valerio Pruneri, and Morgan W. Mitchell

A fast random number generator based on laser dynamics helps test the foundations of quantum physics.

[Phys. Rev. Lett. 115, 250403] Published Wed Dec 16, 2015

Article

Efficient steam generation under solar irradiation is of interest for energy harvesting applications. Here, Bae et al. develop a plasmonic nanofocusing film consisting of metal coated alumina nanowires to efficiently generate solar vapour with an efficiency up to 57% at 20 kWm −2 .

Nature Communications doi: 10.1038/ncomms10103

Authors: Kyuyoung Bae, Gumin Kang, Suehyun K. Cho, Wounjhang Park, Kyoungsik Kim, Willie J. Padilla

Hovertext: DID MY ANALOGY ABOUT BEES MEAN NOTHING TO YOU?!

Author(s): Clément Sayrin, Christian Junge, Rudolf Mitsch, Bernhard Albrecht, Danny O’Shea, Philipp Schneeweiss, Jürgen Volz, and Arno Rauschenbeutel

A proof-of-principle experiment allows single photons to travel in only one direction through an optical fiber.

[Phys. Rev. X 5, 041036] Published Fri Dec 04, 2015

Two journals published by Elsevier are retracting a pair of material science papers that appear to share figures. The papers  — in Materials Letters and Optics Communications — discuss photonic crystals, a kind of material used to manipulate light. They share the same first author, Zheng-qi Liu at Jiangxi Normal University and  Nanjing University in China, as well as […]

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