Free-Space Graphics with Electrically Driven Levitated Light Scatterers

Levitation of optical scatterers provides a new mean to develop free-space volumetric displays. The principle is to illuminate a levitating particle displaced at high velocity in three dimensions (3D) to create images based on persistence of vision (POV). Light scattered by the particle can be observed all around the volumetric display and therefore provides a true 3D image that does not rely on interference effects and remains insensitive to the angle of observation. The challenge is to control with a high accuracy and at high speed the trajectory of the particle in three dimensions. Systems that use light to generate free-space images either in plasma or with a bead are strictly dependent of the scanning method used. Mechanical systems are required to scan the particles in the volume which weakens the time dynamics. Here we use electrically driven planar Paul traps (PPTs) to control the trajectory of electrically charged particles. A single gold particle colloid is manipulated in three dimensions through AC and DC electrical voltages applied to a PPT. Electric voltages can be modulated at high frequencies (150 kHz) and allow for a high speed displacement of particles without moving any other system component. The optical scattering of the particle in levitation yields free-space images that are imaged with conventional optics. The trajectory of the particle is entirely encoded in the electric voltage and driven through stationary planar electrodes. We show in this paper, the proof-of-concept for the generation of 3D free space graphics with a single electrically scanned particle

Long distance manipulation of a levitated nanoparticle in high vacuum

Accurate delivery of small targets in high vacuum is a pivotal task in many branches of science and technology. Beyond the different strategies developed for atoms, proteins, macroscopic clusters and pellets, the manipulation of neutral particles over macroscopic distances still poses a formidable challenge. Here we report a novel approach based on a mobile optical trap operated under feedback control that enables long range 3D manipulation of a silica nanoparticle in high vacuum. We apply this technique to load a single nanoparticle into a high-finesse optical cavity through a load-lock vacuum system. We foresee our scheme to benefit the field of optomechanics with levitating nano-objects as well as ultrasensitive detection and monitoring.Comment: 12 pages 5 figure

In-plane remote photoluminescence excitation of carbon nanotube by propagating surface plasmon

In this work, we demonstrate propagating surface plasmon polariton (SPP) coupled photoluminescence (PL) excitation of single-walled carbon nanotube (SWNT). SPPs were launched at a few micrometers from individually marked SWNT, and plasmon-coupled PL was recorded to determine the efficiency of this remote in-plane addressing scheme. The efficiency depends upon the following factors: (i) longitudinal and transverse distances between the SPP launching site and the location of the SWNT and (ii) orientation of the SWNT with respect to the plasmon propagation wave vector (k SPP). Our experiment explores the possible integration of carbon nanotubes as a plasmon sensor in plasmonic and nanophotonic devices

Does the market value the affiliation of French firms with the UN Global Compact

The UN Global Compact Leaders Summit held in New York on June 2010 marked the 10th anniversary of the UN Global Compact (Adams and Petrella, 2010). From its humble beginnings in 2000, the Global Compact has grown to encompass more than 8,700 corporate participants and others stakeholders, including over 7,700 businesses from 130 countries around the world. It is the world’s largest voluntary corporate responsibility initiative. The benefits for companies voluntarily affiliating with the UN Global Compact have been little documented from an empirical perspective. This affiliation is on a voluntary basis, which raises questions about the integration of this information by capital markets. This study attempts to address these questions, drawing on a sample of French companies listed on the SBF 250 index. Results suggest that, in the French context, investors do not significantly value firm's affiliation with the UN Global Compact

Spontaneous hot-electron light emission from electron-fed optical antennas

Nanoscale electronics and photonics are among the most promising research areas providing functional nano-components for data transfer and signal processing. By adopting metal-based optical antennas as a disruptive technological vehicle, we demonstrate that these two device-generating technologies can be interfaced to create an electronically-driven self-emitting unit. This nanoscale plasmonic transmitter operates by injecting electrons in a contacted tunneling antenna feedgap. Under certain operating conditions, we show that the antenna enters a highly nonlinear regime in which the energy of the emitted photons exceeds the quantum limit imposed by the applied bias. We propose a model based upon the spontaneous emission of hot electrons that correctly reproduces the experimental findings. The electron-fed optical antennas described here are critical devices for interfacing electrons and photons, enabling thus the development of optical transceivers for on-chip wireless broadcasting of information at the nanoscale

Two-Color Dark-Field (TCDF) microscopy for metal nanoparticles imaging inside cells

Noble metal nanoparticles (NPs) supporting localized surface plasmon resonances are widely used in the context of biotechnology as optical and absorption contrast agents with great potential applicability to both diagnostics and less invasive therapies. In this framework, it is crucial to have access to simple and reliable microscopy techniques to monitor the NPs that have internalized into cells. While dark field (DF) microscopy takes advantage of the enhanced NPs scattering at their plasmon resonance, its use in cells is limited by the large scattering background from the internal cell compartments. Here, we report on a novel two-color dark field microscopy that addresses these limitations by significantly reducing the cell scattering contribution. We first present the technique and demonstrate its enhanced contrast, specificity and reliability for NP detection compared to standard optical dark field. We then demonstrate its potential suitability in two different settings, namely wide-field parallel screening of circulating cells in microfluidic chip and high-resolution tracking of internalized NPs in cells. These proof of principle experiments show a promising capability of this approach with possible extension to other kinds of targeted systems like bacteria and vesicles.Peer ReviewedPostprint (author's final draft