Search results for "Dispersion."
showing 10 items of 1094 documents
Multi-model ensemble simulations of olive pollen distribution in Europe in 2014
2017
Abstract. A 6-models strong European ensemble of Copernicus Atmospheric Monitoring Service (CAMS) was run through the season of 2014 computing the olive pollen dispersion in Europe. The simulations have been compared with observations in 6 countries, members of the European Aeroallergen Network. Analysis was performed for individual models, the ensemble mean and median, and for a dynamically optimized combination of the ensemble members obtained via fusion of the model predictions with observations. The models, generally reproducing the olive season of 2014, showed noticeable deviations from both observations and each other. In particular, the season start was reported too early, by 8 days …
Suspended core tellurite glass optical fibers for infrared supercontinuum generation
2011
International audience; We report the fabrication and characterization of tellurite TeO(2)-ZnO-Na(2)O (TZN) microstructured suspended core optical fibers (MOFs). These fibers are designed for infrared supercontinuum generation with zero dispersion wavelength (ZDW) at 1.451 mu m. The measured losses at this wavelength are approximately 6 dB/m for a MOF with a 2.2 mu m diameter core. The effective area of a particular fiber is 3.5 mu m(2) and the nonlinear coefficient is calculated to be 437 W(-1)km(-1). By pumping a 20 cm long fiber at 1.56 mu m with a sub-nj femtosecond laser source, we generate a supercontinuum (SC) spanning over 800 nm in the 1-2 mu m wavelength range.
Polarization Modulation Instability in All-Normal Dispersion Microstructured Optical Fibers With Quasi-Continuous Pump
2019
We report the experimental observation of the polarization modulation instability (PMI) effect in all-normal dispersion (ANDi) microstructured optical fibers (MOFs) with quasi-continuous pumping. The small unintentional birefringence (~10-5), that any realistic non-polarization maintaining MOF exhibits, contributes to this nonlinear effect. PMI can produce two sidebands whose polarization state is orthogonal to the polarization of the pump. In this work, only one type of PMI process is observed, i.e., when the pump is polarized along the slow axis of the fiber and sidebands are generated in the fast axis mode. This PMI process was studied experimentally in two ANDi fibers with different dis…
Time dispersion characterization for UWB mobile radio channels between 3.1 and 10.6 GHz
2007
In this paper, a characterization of the UWB mobile radio channel time dispersion is presented. The results provided were obtained from a measurement campaign carried out in a typical indoor office scenario in the band from 3.1 to 10.6 GHz. Time dispersion metrics as delay spread, coherence bandwidth, delay interval and delay window, in both line-of-sight (LOS) and non-line-of-sight (NLOS) conditions are provided.
Analysis of Fiber Inhomogeneity Using Time-Resolved Acousto-Optic Interaction
2013
Workshop on Specialty Optical Fibers and their Applications 2013, Sigtuna Sweden, 28–30 August 2013
Optimization of dual-core and microstructure fiber geometries for dispersion compensation and large mode area
2009
We investigate dual concentric core and microstructure fiber geometries for dispersion compensation. Dispersion values as large as -59 000 ps/(nm km) are achieved, over a broad wavelength range with full width at half maximum exceeding 100 nm. The trade-off between large dispersion and mode area is studied. Geometries with an effective mode area of 30 microm2 and dispersion -19 000 ps/(nm km) and 80 microm2 with -1600 ps/(nm km) are proposed.
Acousto-Optic Interaction for Accurate Two-Mode Optical Fibers Characterization
2016
Accurate characterization of two-mode fibers by acousto-optic interaction is reported. Difference of modal index, group delay, and dispersion between the guided modes is obtained. Properties of the vector modes comprising the LP11 mode are investigated.
Analytical design of 160 Gbits/s densely dispersion-managed optical fiber transmission systems using Gaussian and raised cosine RZ ansätze
2004
We present an easy and efficient analytical method to design 160 Gbits/s densely dispersion-managed optical fiber transmission systems using Gaussian and raised cosine RZ ansatze.
Polarization mode dispersion and vectorial modulational instability in air silica microstructure fiber
2002
The birefringence of an air-silica microstructure fiber has been studied by measurement of the fiber polarization mode dispersion (PMD) over the wavelength range 545-640 nm. The experimental results are shown to be in good agreement with vectorial numerical calculations, assuming an elliptical core with an eccentricity of 7%. We also report controlled experiments studying nonlinear vectorial modulation instability in the fiber, yielding 3.9-THz modulational instability sideband shifts that are in good agreement with theoretical predictions based on the calculated fiber dispersion and PMD characteristics.
Actively mode-locked fiber ring laser by intermodal acousto-optic modulation
2010
We report an actively mode-locked fiber ring laser. A simple and low-insertion-loss acousto-optic modulator driven by standing flexural waves, which couples core-to-cladding modes in a standard single-mode optical fiber, is used as an active mechanism for mode locking. Among the remarkable features of the modulator, we mention its high modulation depth (72%), broad bandwidth (187 GHz), easy tunability in the optical wavelength, and low insertion losses (0.7 dB). The narrowest optical pulses obtained were of 95 ps time width, 21 mW peak power, repetition rate of 4.758 MHz, and 110 mW of pump power.