Search results for "erbium"
showing 10 items of 253 documents
Optical solitons in erbium doped fibers with higher order effects
2000
Abstract We consider the coupled system of higher order nonlinear Schrodinger equation and Maxwell–Bloch (HNLS–MB) equations, which governs the nonlinear wave propagation in erbium doped optical waveguides in presence of important higher order effects. We present the Lax pair and using Backlund transformation exact soliton solutions are generated.
β-decay study of150Er,152Yb, and156Yb: Candidates for a monoenergetic neutrino beam facility
2011
The beta decays of ^{150}Er, ^{152}Yb, and ^{156}Yb nuclei are investigated using the total absorption spectroscopy technique. These nuclei can be considered possible candidates for forming the beam of a monoenergetic neutrino beam facility based on the electron capture (EC) decay of radioactive nuclei. Our measurements confirm that for the cases studied, the EC decay proceeds mainly to a single state in the daughter nucleus.
Non-existence of dark solitons in a nonlinear Schrödinger-Maxwell-Bloch fibre system
2000
We consider the coupled system of nonlinear Schrodinger and Maxwell-Bloch (NLS-MB) equations, which govern the nonlinear pulse propagation in erbium doped optical fibres. With the help of the Painleve singularity structure analysis, we prove the non-existence of optical solitons in the NLS-MB fibre system in the normal dispersion regime.
Confirming band assignments in $^{167}$ytterbium with gamma-gamma-electron triple-coincidence spectroscopy
2019
International audience; Multipolarity measurements are presented for transitions in the deformed odd-mass nucleus$^{167}$ Yb in support of tentative spin assignments and level interpretations based upon the cranked-Nilsson model. Internal-conversion coefficients were measured with the SAGE (Silicon And GErmanium) spectrometer confirming several E2 transition assignments. The array of high-purity germanium detectors enabled the recording of high-multiplicity events from which $\gamma\gamma\gamma$ and $\gamma\gamma e^{-}$ data sets were extracted and the technique of high-fold $\gamma$ -ray gating was demonstrated to cleanly isolate transitions of interest.
Limits of terrestrial optical fiber systems for ultra-high bit rate RZ data transmissions (from 160 Gbit/s to 1.28 Tbit/s)
2007
This article numerically investigates the fundamental limits of the terrestrial RZ data transmission systems based on SMF/DCF dispersion map for bit rates ranging from 160 Gbit/s to 1.28 Tbit/s. The system includes an erbium doped fiber amplifier and pre-and post-compensation stages. After filtering and detection, the system performance is characterized using the usual Q-factor.
Noise fiber lasers
2021
In this paper, we present a brief review of the noise operation mode of fiber lasers. These lasers were studied recently by collaborative group that includes researchers, professors, and Ph.D. students from the Centro de Investigaciones en Optica, A.C. (Leon, Guanajuato, Mexico) and from the Universidad de Valencia (Valencia, Spain). Meanwhile, the pioneer works in this topic important for understanding the physics behind fiber lasers’ operation and for practical applications were done with the active participation of Dr. Evgeny Kuzin from the Instituto Nacional de Astrofisica, Optica y Electronica (Puebla, Mexico) and Dr. Georgina Beltrán-Pérez from the Benemérita Universidad Autónoma de P…
Role of field losses on the Risken?Nummedal?Graham?Haken laser instability: application to erbium-doped fibre lasers
2003
We analyse the effect of both distributed and localised losses in a laser cavity on the Risken–Nummedal–Graham–Haken multimode instability. For two-level lasers, distributed losses are found to have a negligible influence on the instability conditions as long as they remain below 10 dB, a value hardly ever exceeded under common experimental conditions. If one keeps raising the distributed loss above that value, finally the uniform-field-limit results are recovered: localised loss becomes less and less important, and in the limit does not enter at all. In contrast, for three-level lasers – in particular for erbium-doped fibre lasers – distributed losses are found to have a profound quantitat…
Dynamic Characterization of Upconversion in Highly Er-Doped Silica Photonic Crystal Fibers
2012
Measurements of time evolution of amplified spontaneous emission for square-wave modulated pump were made on a highly erbium-doped silica photonic crystal fiber and fitted to theoretical results calculated using different formalisms to describe the ${\rm Er}^{3+}$ -ion migration-assisted co-operative upconversion mechanism in the population densities rate equations. The determined characterization parameters are the constant homogeneous upconversion coefficient, 3.0 $\times 10^{-24}~{\rm m}^{3}/{\rm s}$ , the critical radii for upconversion and migration, 10.5 and 14A, respectively, and the rate of clustered ions, 14%. These parameters are analysed and compared to those obtained with contin…
Luminescence properties of Tb3+:Y3Al5O12 nanocrystallites prepared by the sol–gel method
2004
Tb 3+ :YAG nanocrystalline powders have been prepared by the sol-gel route. Structure and morphology of the obtained materials have been studied. The average grain sizes have been determined by X-ray powder diffraction measurements. Photo- and cathodoluminescence spectra of the Tb 3+ :Y 3 Al 5 O 12 powders have been measured. It has been found that the samples at low concentration demonstrate emission ascribable to the 5 D 3 →F J and 5 D 4 → 7 F J transitions. In particular, the concentration dependence of the luminescence spectra and lifetimes have been investigated as a function of the YAG grains sizes. It has been shown that the cross-relaxation responsible for the quenching of the 5 D 3…
Photoluminescence of neodymium and erbium doped NaLaF4 material
2013
Abstract In the course of this research several NaLaF 4 samples doped with different Er 3+ and Nd 3+ concentrations have been synthesized. For these samples photoluminescence spectra, kinetics and excitation spectra have been measured. It has been found that when samples containing Nd 3+ and Er 3+ impurities are excited in specific Nd 3+ bands not only Nd 3+ but also Er 3+ luminescence bands appear. The studies of the decay kinetics show that there is an energy transfer from Nd 3+ to Er 3+ , moreover “green” and “red” Er 3+ luminescence bands appear as result of two different energy transfer mechanisms. In addition, photoluminescence processes in Nd 3+ ions are investigated. Based on the ob…