Search results for "Waveguide"
showing 10 items of 311 documents
Interacting Solitons in a High Index Glass
2010
We investigate the interaction of two coherent 2D+1 solitary beams in a high index glass.
Efficient Pole Expansion of the Generalized Impedance Matrix Representation for Planar Waveguide Junctions
2006
This paper proposes a novel pole expansion of the generalized impedance matrix representation for planar waveguide junctions. Proceeding in this way, we have obtained a very efficient algorithm for the accurate wide-band modelling of such junctions, since the most expensive computations are performed outside the frequency loop. For verification purposes, several practical examples are shown in order to prove the numerical efficiency and accuracy provided by this new technique.
Asymptotic and Numerical Studies of Resonant Tunneling in 2D-Waveguides for Electrons of Small Energy
2021
Chapter 5 is devoted to asymptotic studies of electron resonant tunneling in a two-dimensional waveguide with two narrows. The narrow diameter plays the role of a small parameter. The asymptotics of basic characteristics of resonant tunneling are presented for electrons with energy between the first and the second thresholds. Moreover, the asymptotics results are compared with numerical ones obtained by approximate calculation of the scattering matrix.
Multipactor Analysis in Circular Waveguides
2009
[EN] This paper mainly focuses on demonstrating that a multipactor discharge can occur within a circular waveguide operating under the fundamental TE11 circular mode. Circular waveguides are widely used in the fabrication of many passive components, in order to implement resonant cavities as well as irises to connect adjacent guides for both application domains, particle accelerators and satellite subsystems applications. Thus, we present the first study of the multipactor effect in a circular waveguide, demonstrating its existence and providing a susceptibility chart for such a structure, which will be of great interest for the better understanding of multipactor physical phenomena.
Large data scattering for NLKG on waveguide ℝd × 𝕋
2020
We consider the pure-power defocusing nonlinear Klein–Gordon equation, in the [Formula: see text]-subcritical case, posed on the product space [Formula: see text], where [Formula: see text] is the one-dimensional flat torus. In this framework, we prove that scattering holds for any initial data belonging to the energy space [Formula: see text] for [Formula: see text]. The strategy consists in proving a suitable profile decomposition theorem on the whole manifold to pursue a concentration-compactness and rigidity method along with the proofs of (global in time) Strichartz estimates.
Triply resonant coherent four-wave mixing in silicon nitride microresonators
2015
The generation of multiple tones using four-wave mixing (FWM) has been exploited for many applications, ranging from wavelength conversion to frequency comb generation. FWM is a coherent process, meaning that its dynamics strongly depends on the relative phase among the waves involved. The coherent nature of FWM has been exploited for phase-sensitive processing in different waveguide structures, but it has never been studied in integrated microresonators. Waveguides arranged in a resonant way allow for an effective increase in the wavelength conversion efficiency (at the expense of a reduction in the operational bandwidth). In this letter, we show that phase shaping of a three-wave pump pro…
Quadratic solitons in 2D nonlinear photonic crystals
2007
We report on the first observation of spatial solitons in a 2D nonlinear photonic crystal. The experiments were performed in an hexagonally poled LiNbO3 waveguide designed for second harmonic generation from ~1.55 micron.
Acousto-optical multiple interference switches
2007
The authors introduce an alternative approach for acousto-optical light control based on the interference of light propagating through several waveguides, each subjected to a periodic refractive index modulation induced by a surface acoustic wave. The feasibility of the concept is demonstrated by the realization of an optical switch for arbitrary time intervals with an on/off contrast ratio of 20.
Quantum motion of a neutron in a wave-guide in the gravitational field
2006
We study theoretically the quantum motion of a neutron in a horizontal waveguide in the gravitational field of the Earth. The waveguide in question is equipped with a mirror below and a rough surface absorber above. We show that such a system acts as a quantum filter, i.e. it effectively absorbs quantum states with sufficiently high transversal energy but transmits low-energy states. The states transmitted are determined mainly by the potential well formed by the gravitational field of the Earth and the mirror. The formalism developed for quantum motion in an absorbing waveguide is applied to the description of the recent experiment on the observation of the quantum states of neutrons in th…
Waveguide-QED-based measurement of a reservoir spectral density
2015
The spectral density (SD) function has a central role in the study of open quantum systems (OQSs). We discover a method allowing for a "static" measurement of the SD - i.e., it requires neither the OQS to be initially excited nor its time evolution tracked in time - which is not limited to the weak-coupling regime. This is achieved through one-dimensional photon scattering for a zero-temperature reservoir coupled to the OQS via the rotating wave approximation. We find that the SD profile is a universal simple function of the photon's reflectance and transmittance. As such, it can be straightforwardly inferred from photon's reflection and transmission spectra.