10 research outputs found
Resonant Laser Ionization and Fine-Structure Study of Silver in an Ablation Plume
We report on a laser photo-ionization study of silver in relation to the Selective Production of Exotic Species (SPES) project at INFN-LNL in the offline laser laboratory. In this study, two dye lasers and an ablation laser operating at 10 Hz are used alongside a time-of-flight mass spectrometer (TOF-MS). Isotopic separation of the natural, stable isotopes 107Ag and 109Ag was clearly observed in the TOF signal. Resonant photo-ionization of silver was achieved with the use of the scheme 4d105s 2S1/2→ 4d105p 2Po3/2→ 4d106d 2D3/2 with transition wavelengths of 328.163 nm and 421.402 nm, respectively. Doppler-suppressed spectroscopy of these transition lines was performed in an ablation plume. Doppler broadening with collinear injection of excitation lasers and the effect of the linewidths of the excitation lasers were investigated. The fine-structure splitting of the level 4d106d 2D (J = 5/2 and J = 3/2) was confirmed to be 186 ± 2 pm, corresponding to 314 ± 3 GHz
Cascade Superfluorescence in Er:YLF
We report the analysis of paired photon pulses arising from two cascading
transitions in continuously pumped Erbium-doped YLiF 1% and 0.01% crystals
at 1.6 K. The dependence of the pulse peak intensity on the squared number of
involved Erbium ions, between 10 and 10, definitely identifies
the cooperative nature of the two pulsed emissions, that are generated by the
subsequent, spontaneous formation of coherent states. The observed fluctuations
of the time interval between the paired pulses and, most importantly, its
correlation with the second pulse duration, demonstrate that the Erbium ions
coherence is indeed seeded by vacuum fluctuations
Enhanced atomic desorption of 209 and 210 Francium from organic coating
Controlled atomic desorption from organic Poly-DiMethylSiloxane coating is demonstrated for improving the loading efficiency of 209,210Fr magneto-optical traps. A three times increase in the cold atoms population is obtained with contact-less pulsed light-induced desorption, applied to different isotopes, either bosonic or fermionic, of Francium. A six times increase of 210Fr population is obtained with a desorption mechanism based on direct charge transfer from a triboelectric probe to the adatom-organic coating complex. Our findings provide new insight on the microscopic mechanisms of atomic desorption from organic coatings. Our results, obtained at room temperature so as to preserve ideal vacuum conditions, represent concrete alternatives, independent from the atomic species in use, for high-efficiency laser cooling in critical conditions
Buffer gas-assisted four-wave mixing resonances in alkali vapor excited by a single cw laser
We report the observation of a fluorescence peak appearing in dilute alkali (Rb, Cs) vapor in the presence of a buffer gas when the cw laser radiation frequency is tuned between the Doppler-broadened hyperfine transition groups of an atomic D2 line. Based on steep laser radiation intensity dependence above the threshold and spectral composition of the observed features corresponding to atomic resonance transitions, we have attributed these features to the buffer gas-assisted four-wave mixing process
Magnetic-field-compensation optical vector magnetometer
A concept for an optical magnetometer used for the measurement of magnitude and direction of a magnetic field (B-field) in two orthogonal directions is developed based on double scanning of a B-field to compensate the measured field to zero value, which is monitored by a resonant magneto-optical process in an unshielded atomic vapor cell. Implementation of the technique using the nonlinear Hanle effect on the D2 line of rubidium demonstrates viability and efficiency of the proposed concept. The ways to enhance characteristics of the suggested technique and optimize its performance, as well as the possible extension to three-axis magnetometry, are discussed
New ideas on prospective low energy threshold detectors for dark matter searches
Low energy threshold detectors are necessary in many frontier fields of experimental physics. In particular, these are extremely important for probing possible dark matter (DM) candidates. We present a novel detection approach that exploits the energy levels of atoms maintained at cryogenic temperature. We exploit laser-assisted transitions that are triggered by the absorption of the incident particle in the material and lead to the emission of a fluorescent photon or an electron. In this approach, the incident particle will in fact excite the first low-lying energy level that is then up-converted using an opportune narrow-band laser system. Two different detection schemes are thus possible in our active material: one is based on a photon signal while the other takes advantage of high efficiency in-vacuum charge detection
Spectroscopy of Rubidium atoms in solid matrices of rare gases: experimental results and theoretical analysis
We present an experimental and theoretical investigation of the spectroscopy
of dilute alkali atoms in a solid matrix of inert gases at cryogenic
temperatures, specifically Rubidium atoms in a solid Argon or Neon matrix, and
related aspects of the interaction energies between the alkali atoms and the
atoms of the solid matrix. The system considered is relevant for matrix
isolation spectroscopy, and it is at the basis of a recently proposed detector
of cosmological axions, exploiting magnetic-type transitions between Zeeman
sublevels of alkali atoms in a magnetic field, tuned to the axion mass, assumed
in the meV range. Axions are one of the supposed constituents of the dark
matter (DM) of the Universe. This kind of spectroscopy could be also relevant
for the experimental search of new physics beyond the Standard Model, in
particular the search of violations of time-reversal or
parity-charge-conjugation (CP) symmetry. In order to efficiently resolve the
axion-induced transition in alkali-doped solid matrices, it is necessary to
reduce as much as possible the spectral linewidth of the electronic transitions
involved. The theoretical investigation presented in this paper aims to
estimate the order of magnitude of the inhomogeneous contribution to the
linewidth due to the alkali--matrix interactions (Coulomb/exchange and
dispersion), and to compare the theoretical results with our experimental
measurements of spectra of dilute Rubidium atoms in Argon and Neon solid
matrix. The comparison of the expected or measured spectral linewidths will be
important for selecting the most appropriate combination of alkali atoms and
matrix inert elements to be used in the proposed axion detection scheme. It is
finally suggested that dilute Lithium atoms diffused in a cold parahydrogen
solid matrix could be, overall, a good system upon which the proposed detector
could be based.Comment: 16 pages, 6 figure
Buffer gas-assisted four-wave mixing resonances in alkali vapor excited by a single cw laser
Forty years after the first dark resonance experiment: an overview of the COSMA project results
Coherent Optics Sensors for Medical Applications (COSMA) was a European Marie Curie Project running from 2012 to 2016, with the participation of 10 teams from Armenia, Bulgaria, India, Israel, Italy, Poland, Russia, UK and USA. The main objective was to focus theoretical and experimental research on biomagnetic phenomena, with the specific aim to develop all-optical sensors dedicated to their detection and suitable for applications in clinical diagnostics. The paper presents some of the most recent non–technical results obtained during the exchange visits of the involved scientists, after an introduction about the phenomenon which is the pillar of this kind of research and of many other new fields in laser spectroscopy, atomic physics and quantum optics