Search results for "Optoelectronics"

Towards Si-based photonic circuits: Integrating photonic crystals in silicon-on-insulator platforms

2007

In the context of Si-based photonics, we report on a strategy to integrate two optical components, a 3D photonic crystal light emitter and a waveguide, in a silicon-on-insulator patterned substrate. Self-assembled colloidal photonic crystals are produced with high crystalline quality and spatial selectivity. Plane wave expansion and finite-difference time-domain have been used to find suitable configurations for positioning emitters and waveguides. The first steps toward the realisation of these configurations are presented.

Influence of mobile ions on the electroluminescence characteristics of methylammonium lead iodide perovskite diodes

2016

In this work, we study the effect of voltage bias on the optoelectronic behavior of methylammonium lead iodide planar diodes. Upon biasing the diodes with a positive voltage, the turn-on voltage of the electroluminescence diminishes and its intensity substantially increases. This behavior is reminiscent of that observed in light-emitting electrochemical cells (LECs), single-layer electroluminescent devices in which the charge injection is assisted by the accumulation of ions at the electrode interface. Because of this mechanism, performances are largely independent from the work function of the electrodes. The similarities observed between planar perovskite diodes and LECs suggest that mobi…

Optimization of surface plasmons launching from subwavelength hole arrays: modelling and experiments

2009

International audience; The launching of surface plasmons by micro-gratings of subwavelength apertures milled in a thick metal film is important for the development of surface plasmon based circuits. By comparing the near-field optical images of such surface plasmon sources with the results of a Huygens-Fresnel principle based scattering model, we show that the properties of the locally launched SP beams such as divergence or uniformity can be tuned by adjusting the shape of the micro-gratings. This allows us to propose an optimized source array well adapted for providing a narrow, collimated and uniform beam. (c) 2007 Optical Society of America.

Design scaling laws for self-phase modulation-based 2R-regenerators

2006

We report global scaling laws linking the design of SPM-based 2R-regenerators to their ability to reduce amplitude noise and improve the signal extinction ratio.

Magnetic Domain Imaging with a Photoemission Microscope

1997

ABSTRACTPhotoelectron emission microscopy (PEEM) has proven to be a versatile analytical technique in surface science. When operated with circularly polarized light in the soft x-ray regime, however, photoemission microscopy offers a unique combination of magnetic and chemical information. Exploiting the high brilliance and circular polarization available at a helical undulator beamline, the lateral resolution in the imaging of magnetic domain structures may be pushed well into the sub-micrometer range. Using a newly designed photoemission microscope we show that under these circumstances not only domains, but also domain walls can be selectively investigated. The high sensitivity of the te…

Optical and structural studies of GaN 3D structures selectively grown by MOCVD

2004

Abstract This paper presents preliminary results on the selective growth of three-dimensional (3D) micrometric metallic structures by the MOCVD technique. The 3D structure growth occurs by simply feeding the reactor gas phase with a conventional flow of metal-organic (MO), trimethyl-gallium (TMGa) molecules. Selectivity occurs at the substrate surface in which MO species travel tens of micrometers in order to build up the 3D structure. After the growth, these structures are nitrided in order to give GaN-related optical visible emission. Optical emission results are presented and discussed in this paper. Both 3D structures deposition and annealing experiments can be extended to other III–V m…

Watching Ions Move: Scanning Probe Microscopy on Perovskite Solar Cells

2018

Experimental demonstration of an ultrafast all-optical bit-error indicating scheme

2010

International audience; We experimentally demonstrate an all-optical bit error monitoring scheme based on the self-phase modulation occurring during the propagation in a highly nonlinear fiber followed by an optical bandpass filter. Numerical simulations are confirmed by experimental observations performed at a repetition rate of 40 Gb/s.

Logic gates scheme based on Coulomb blockade in metallic nanoclusters with organic ligands

2010

We propose a logic gates scheme based on the electron transfer through metallic nanoclusters linked to organic ligands and discuss theoretically the characteristics needed for practical implementation. As a proof-of-the-concept, we demonstrate the OR, AND and NOT gates and study the performance in terms of temperature, applied voltage, and noise.

Sensitivity of SHG-FROG for the characterization of ultrahigh-repetition-rate telecommunication laser sources

2004

International audience; We analyze experimentally the sensitivity of second-harmonic generation frequency-resolved optical gating (SHG-FROG) for the complete intensity and phase characterization of both a sinusoidal beat signal and a train of 1.3 ps pulses at a repetition rate of 160 GHz at 1550 nm. Using a commercially-available optical spectrum analyzer in the SHG-FROG set-up, incident pulses with energies of only 125 and 190 fJ, which correspond to the beat signal and the 1.3 ps pulse train, respectively, have been accurately characterized.