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We study optical field emission from silver nanotips, showing the combined influence of the illumination wavelength and the exact shape of the nanotip on the strong-field response. This is particularly relevant in the case of FIB milled nano tips, where the nanotip fabrication capabilities could become a new ingredient for the study of strong-field physics. The influence of the thermal load on the nanotip and its effect on the emission is studied as well by switching the repetition rate of the laser source from 1 kHz to 62 MHz, showing a clear transition towards the quenching of the strongfield emission.
Bell's inequality violation experiments are becoming increasingly popular in the practical teaching of undergraduate and master's degree students. Bell's parameter S is obtained from 16 polarization correlation measurements performed on entangled photons pairs. We first report here a detailed analysis of the uncertainty u(S) of Bell's parameter taking into account coincidence count statistics and errors in polarizers' orientation. We show using both computational modeling and experimental measurement that the actual sequence of the polarizer settings has an unexpected and strong influence on the error budget. This result may also be relevant to measurements in other settings in which errors in parameters may have non-random effects in the measurement.
We report results of experimental investigation of field electron emission from diamond nanoemitters. The measurements were performed with single crystal diamond needles fixed at tungsten tips. The voltage drop along diamond needles during emission was revealed and measured using electron energy spectroscopy. The observed linear dependence of the voltage drop in diamond on voltage applied to the tungsten tip is explained in the frame of a simple macroscopic electrical model combining Poole–Frenkel conduction along the diamond tip and Fowler–Nordheim tunneling at the diamond-vacuum junction. Experimental evidences of electron emission sensitivity to laser illumination are discussed for possible modification of diamond emitter characteristics and voltage drop.
High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20–26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected.
Sujets
Extreme ultraviolet
Femtosecond pulses
7867Pt
Factorization
Acétylène
Caractérisation spatio-temporelle
Quantum dots
Ultrafast nonlinear optics
Wave packet interferences
Contrôle cohérent
Femtosecond spectroscopy
Caractérisation complète
Attosecond
Ultrashort lasers
Femtosecond laser
Quantum path interferences
XUV
Génération d'harmoniques d'ordre élevé
Cold molecules
Molecular dynamics
Pulse shaping
Femtoseconde
Coherent Transient
Diamond nanotip
Azulene
Complete characterization
Dynamique moléculaire
Rubidium atom
Pump-probe
Optical Parametric Amplifier
Coherent transients
Coherent Transients
Gauss sums
Contrôle spatio-temporel
4265Re
Femtochemistry
Autocorrelation function
Femtosecond lasers
Factorisation
Time-resolved photoelectron spectroscopy
CHARGE-TRANSFER
Mise en forme d'impulsions
Photoémission
Oscillations de Rabi
Number theory
Spin-orbit precession
Attoseconde
AOPDF
C2H2
Anharmonicity
Chirp modulation rotational states quantum theory energy level crossing laser beams dissociation
Chlorine azide
Half revival
Bell's inequality
Atom-photon collisions
Impulsions à dérive de fréquence
Ultraviolet
Expérience pompe-sonde
ClN3
ALIGNED MOLECULES
Rabi oscillations
Chirped laser pulses
4265Ky
Velocity map imaging
Caractérisation
Ultrashort pulses
Diffractive optical element
Coherent pulse propagation
Echantillon multidiffusant
CIN3
Chirped pulses
7960Jv
4225Ja
Passage adiabatique rapide
ATOMS
Coherent control
Cold Molecules
Mise en forme d'impulsion
Femtosecond
Transitoires cohérents
Femtosecond pulse
Characterisation
Excited states sodium
4230Kq
ELEMENTAL FRACTIONATION
Couplage spatio-temporel
Azoture de chlore
Boîte quantique semiconductrice
ENERGY
CHLORINE AZIDE
Emission par champ froid
Adiabatic rapid passage
Champ fort
Expériences pompe-sonde
Interférences de chemins quantiques
NO2
Photoemission
Quantum state measurement
Cold field emission
CYCLIC-N-3