Search results for "waveguides."
showing 10 items of 62 documents
Exploring titanium dioxide as a new photonic platform
2019
International audience; We report the development of titanium dioxide-based waveguides for applications in the near-and mid-infrared. Thanks to embedded metal grating couplers, we demonstrate error free 10 Gbit/s optical transmissions at 1.55 and 2 µm. We also demonstrate octave-spanning supercontinuum in cm-long waveguides. We explore the way to improve such waveguides through optimized fabrication process.
MWP phase shifters integrated in PbS-SU8 waveguides
2015
[EN] We present new kind of microwave phase shifters (MPS) based on dispersion of PbS colloidal quantum dots (QDs) in commercially available photoresist SU8 after a ligand exchange process. Ridge PbS-SU8 waveguides are implemented by integration of the nanocomposite in a silicon platform. When these waveguides are pumped at wavelengths below the band-gap of the PbS QDs, a phase shift in an optically conveyed (at 1550 nm) microwave signal is produced. The strong light confinement produced in the ridge waveguides allows an improvement of the phase shift as compared to the case of planar structures. Moreover, a novel ridge bilayer waveguide composed by a PbS-SU8 nanocomposite and a SU8 passive…
Soft proton exchanged channel waveguides in congruent lithium tantalate for frequency doubling
2010
We report on stable optical waveguides fabricated by soft-proton exchange in periodically-poled congruent lithium tantalate in the a-phase. The channel waveguides are characterized in the telecom wavelength range in terms of both linear properties and frequency doubling. The measurements yield a nonlinear coefficient of about 9.5pm/V, demonstrating that the nonlinear optical properties of lithium tantalate are left nearly unaltered by the process. (C) 2010 Optical Society of America
Multi-line NIR-RGB emission in Nd:LiNbO3 RPE optical waveguides
2007
Simultaneous generation of four spectral emission lines has been achieved in Nd-doped lithium niobate reverse proton exchange optical waveguide cavities. Using a pump at 800 nm, the four lines were found and they are due to lasing at 1.3735 combined with parametric conversion at 0.687, 0.574 and 0.4 mum.
Color Tuning and White Light by Dispersing CdSe, CdTe, and CdS in PMMA Nanocomposite Waveguides
2013
In this paper, active nanocomposite waveguides based on the dispersion of CdS, CdTe, and CdSe colloidal quantum dots (QDs) in PMMA are proposed. Their propagation properties are studied as a function of the concentration of nanoparticles in the polymer using the variable length stripe method. When the three nanostructures are dispersed in the same film, the structure is able to waveguide the three basic colors: red (CdSe), green (CdTe), and blue (CdS), it being possible to engineer any waveguided color by an appropriate choice of the filling factor of each QD in the PMMA matrix. For this purpose, it is important to take into account reabsorption effects and the Förster energy transfe…
Spatial Solitons in Quadratic 2D Nonlinear Photonic Crystals
2007
We report on the first investigations into parametric solitary-wave formation in 2D nonlinear photonic crystals and present experimental results obtained in an hexagonally poled LiNbO3 waveguide designed for twin-beam second harmonic generation at telecom wavelengths.
The role of nonlinear optical absorption in narrowband difference-frequency terahertz-wave generation
2010
We present a general analysis of the influence of nonlinear optical absorption on terahertz generation via optical difference frequency generation, when reaching for the quantum conversion efficiency limit. By casting the equations governing the process in a suitably normalized form, including either two-photon- or three-photon-absorption terms, we have been able to plot universal charts for phase matched optical-to-terahertz conversion for different values of the nonlinear absorption coefficients. We apply our analysis to some experiments reported to date, in order to understand to what extent multiphoton absorption could have played a role and also to predict the maximum achievable conver…
Tapered Two-Wire Waveguide for Time-Domain Integration of Broadband Terahertz Pulses
2021
We show the time-domain integration of terahertz pulses achieved in a sub-wavelength, tapered two-wire waveguide. Both simulation and experimental results prove the time integration functionality of this waveguide topology.
Modelling leaky photonic wires: a mode solver comparison
2006
We present results from a mode solver comparison held within the framework of the European COST P11 project. The structure modelled is a high-index contrast photonic wire in silicon-oninsulator subject to substrate leakage. The methods compared are both in-house developed and commercial, and range from effective index and perturbation methods, over finite-element and finite-difference codes, beam propagation methods, to film mode matching methods and plane wave expansion methods.
Quasideterministic realization of a universal quantum gate in a single scattering process
2012
We show that a flying particle, such as an electron or a photon, scattering along a one-dimensional waveguide from a pair of static spin-1/2 centers, such as quantum dots, can implement a CZ gate (universal for quantum computation) between them. This occurs quasi-deterministically in a single scattering event, hence with no need for any post-selection or iteration, {and} without demanding the flying particle to bear any internal spin. We show that an easily matched hard-wall boundary condition along with the elastic nature of the process are key to such performances.