A5085691886- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Photonic and Optical Devices
- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Mechanical and Optical Resonators
- Atmospheric Ozone and Climate
- Laser Design and Applications
- Photorefractive and Nonlinear Optics
- Strong Light-Matter Interactions
- Solid State Laser Technologies
- Laser-Matter Interactions and Applications
- Advanced Fiber Optic Sensors
- Quantum, superfluid, helium dynamics
- Dark Matter and Cosmic Phenomena
- Quantum Information and Cryptography
- Semiconductor Lasers and Optical Devices
- Geophysics and Sensor Technology
- Photonic Crystal and Fiber Optics
- Quantum Mechanics and Applications
- Optical measurement and interference techniques
- Quantum optics and atomic interactions
- Mass Spectrometry Techniques and Applications
- Atmospheric and Environmental Gas Dynamics
National Institute of Optics
2014-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
2016-2023
National Research Council
2017-2022
Istituto Nazionale di Fisica Nucleare
2015-2022
Angelo State University
2022
Istituto di Fotonica e Nanotecnologie
2015
Politecnico di Milano
2015
Istituto Nazionale di Fisica Nucleare, Sezione di Firenze
2014
Consorzio Roma Ricerche
2006
University of Florence
2000-2005
We report on the direct observation of an oscillating atomic current in a one-dimensional array Josephson junctions realized with Bose-Einstein condensate. The is created by laser standing wave, condensates trapped valleys periodic potential and weakly coupled interwell barriers. coherence multiple tunneling between adjacent wells continuously probed interference. square small-amplitude oscillation frequency proportional to microscopic rate each condensate through barriers provides...
We report the experimental observation of disruption superfluid atomic current flowing through an array weakly linked Bose–Einstein condensates. The condensates are trapped in optical lattice superimposed on a harmonic magnetic potential. dynamical response system to change potential minimum along axis goes from coherent oscillation (superfluid regime) localization trap ('classical' insulator regime). occurs when initial displacement is larger than critical value or, equivalently, velocity...
Continuously pumped passive nonlinear cavities can be harnessed for the creation of novel optical frequency combs. While most research has focused on third-order "Kerr" interactions, recent studies have shown that comb formation also occur via second-order effects. Here, we report quadratic combs in parametric oscillator (OPO) configurations. Specifically, demonstrate generated region around half pump a continuously driven OPO. We model OPO dynamics through single time-domain mean-field...
We experimentally demonstrate and theoretically explain the onset of optical frequency combs in a simple cavity-enhanced second-harmonic-generation system, exploiting second-order nonlinear interactions. Two are simultaneously generated around fundamental pump frequency, with spectral bandwidth up to about 10 nm, its second harmonic. observe different regimes generation, depending on phase-matching condition for second-harmonic generation. Moreover, we develop an elemental model which...
We investigate the properties of a coherent array containing about 200 Bose-Einstein condensates produced in far detuned 1D optical lattice. The density profile gas, imaged after releasing trap, provides information coherence ground-state wavefunction. measured atomic distribution is characterized by interference peaks. time evolution peaks, their relative population as well radial size expanding cloud are good agreement with predictions theory. 2D nature trapped and conditions required to...
Two 87Rb condensates ( F = 2, m(f) and 1) are produced in highly displaced harmonic traps the collective dynamical behavior is investigated. The mutual interaction between two evidenced center-of-mass oscillations as a frequency shift of 6.4(3)%. Calculations based on mean-field theory well describe observed effects periodical collisions both motion shape oscillations.
Among the most powerful techniques for exploration of Universe is very long baseline interferometry (VLBI), which based on simultaneous observation radio sources in sky with arrays distant ground-based antennas. One effects currently limiting its ultimate sensitivity phase-instability reference clocks adopted at each antenna. This term can be made negligible delivering same clock signal to multiple telescope sites using optical fibers. We realized such an infrastructure by disseminating a...
We study the phase transition of a gas Rb atoms to quantum degeneracy in combined potential harmonically confining magnetic trap and periodic an optical lattice. For high lattice potentials we observe significant change temperature dependency population ground state system. The experimental results are explained by subsequent formation quasi 2D condensates single sites.
An optical frequency synthesizer (OFS), based on difference- generation (DFG), is demonstrated at 3 µm. By mixing a near-infrared (IR) OFS and tunable continuous-wave (CW) laser in periodically poled lithium-niobate (PPLN) crystal, new comb created from 2.9 to 3.5 µm (in 180 nm wide spans) with 100 MHz mode spacing. phase-locking, the pump near-IR OFS, mid-IR directly linked Cs primary standard via global positioning system (GPS) time receiver. Then, compactness of our fibre-based set-up...
Thanks to the advent of optical frequency comb synthesizers, based on femto-second mode-locked lasers, field metrology has experienced an extraordinary growth, producing outstanding results in precision spectroscopy and opening new perspectives different metrological branches. After introducing basic concepts, systems experiments, we overview most significant achievements this fast expanding field.
Abstract Quadratic nonlinear processes are currently exploited for frequency comb transfer and extension from the visible near infrared regions to other spectral ranges where direct generation cannot be accomplished. However, has been directly observed in continuously pumped quadratic crystals placed inside an optical cavity. At same time, introductory theoretical description of phenomenon provided, showing a remarkable analogy with dynamics third-order Kerr microresonators. Here, we give...
A 3-microm continuous-wave difference-frequency source is directly referenced to a mid-infrared optical frequency comb synthesizer by measuring their beat-note signal fast HgCdTe detector. Absolute metrology of molecular vibration spectra demonstrated locking the coherent radiation nearest tooth and tuning mode spacing across Doppler-broadened absorption profile CH(4) ro-vibrational transition.
We present a widely-tunable, singly-resonant optical parametric oscillator, emitting more than 1 W between 2.7 and 4.2 μm, which is phase locked to self-referenced frequency comb. Both pump signal frequencies are directly phase-locked the comb of NIR-emitting fs mode-locked fibre laser, linked, in turn, caesium primary standard. estimate for idler fractional Allan deviation ∼ 3 × 10⁻¹²τ⁻½ 200 s. To test spectroscopic performance OPO, we carried out saturation spectroscopy several transitions...
By reducing both the internal and translational temperature of any species down to a few kelvins, buffer-gas-cooling (BGC) technique has potential dramatically improve quality ro-vibrational molecular spectra, thus offering unique opportunities for transition frequency measurements with unprecedented accuracy. However, difficulty in integrating metrological-grade spectroscopic tools into bulky cryogenic equipment hitherto prevented from approaching kHz level even best cases. Here, we...
We present a detection scheme to search for QCD axion dark matter, that is based on direct interaction between axions and electrons explicitly predicted by DFSZ models. The local matter field shall drive transitions Zeeman-split atomic levels separated the rest mass energy $m_a c^2$. Axion-related excitations are then detected with an upconversion involving pump laser converts absorbed ($\sim $ hundreds of $\mu$eV) visible or infrared photons, where single photon established technique....
We demonstrate continuous-wave cavity ring-down spectroscopy of a partially hydrodynamic molecular beam emerging from buffer-gas-cooling source.
Generalizing Sikivie's approach (Sikivie 2014 Phys. Rev. Lett.113 201301), according to which dark matter axions may induce transitions between Zeeman states in an atomic system, experiment based on a molecular gas is proposed for search the axion mass range 1.4 and 1.9 meV. In particular, 16O2 sample brought temperature of 280 mK via buffer-gas cooling then subjected external magnetic field; axion-driven are eventually detected by resonance-enhanced multi-photon ionization spectroscopy.
We report on a comprehensive characterization of Cr 2+ -doped CdSe single crystal as an efficient active material for tunable laser applications in the mid-infrared spectral region.Optical gain, thermo-optical behavior, power efficiency, scalability and wavelength tunability have been thoroughly investigated.Using antireflection-coated pumped by Tmfiber at 1.94 μm, 1-W CW output 50% slope efficiency 2.65 μm emission obtained diffraction-limited beam.An peak 2.5 W has achieved without...
We study low-lying collective modes of an elongated $^{87}\mathrm{R}\mathrm{b}$ condensate produced in a 3D magnetic harmonic trap with the addition 1D periodic potential which is provided by laser standing wave along axial direction. While transverse breathing mode remains unperturbed, quadrupole and dipole oscillations optical lattice are strongly modified. Precise measurements frequencies at different heights barriers provide stringent test theoretical model recently introduced [M....
The electric quadrupole fundamental (v=1←0) band of molecular deuterium around 3 μm is accessed by cavity ring-down spectroscopy using a difference-frequency-generation source linked to the Cs-clock primary standard via an optical frequency comb synthesizer. An absolute determination line position and strength reported for first two transitions (J=2←0 J=3←1) S branch. accuracy 6×10(-8) achieved line-center frequencies, which improves factor 20 previous experimental results [A. R. W. McKellar...