77 research outputs found
Comb-assisted spectroscopy of CO2 absorption profiles in the near- and mid-infrared regions
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Passive mode locking of a Tm,Ho:KY(WO4)(2) laser around 2 μm
We report the first demonstration, to our knowledge, of passive mode locking in a Tm3+, Ho3+-codoped KYWO42 laser operating in the 2000-2060 nm spectral region. An InGaAsSb-based quantum well semiconductor saturable absorber mirror is used for the initiation and stabilization of the ultrashort pulse generation. Pulses as short as 3.3 ps were generated at 2057 nm with average output powers up to 315 mW at a pulse repetition frequency of 132 MHz for 1.15 W of absorbed pump power at 802 nm from a Ti:sapphire laser
Versatile mid-infrared frequency-comb referenced sub-Doppler spectrometer
We present a mid-IR high-precision spectrometer capable of performing accurate Doppler-free measurements with absolute calibration of the optical axis and high signal-to-noise ratio. The system is based on a widely tunable mid-IR offset-free frequency comb and a Quantum-Cascade-Laser (QCL). The QCL emission frequency is offset locked to one of the comb teeth to provide absolute-frequency calibration, spectral-narrowing, and accurate fine frequency tuning. Both the comb repetition frequency and QCL-comb offset frequency can be modulated to provide, respectively, slow- and fast-frequency-calibrated scanning capabilities. The characterisation of the spectrometer is demonstrated by recording sub-Doppler saturated absorption features of the CHF3 molecule at around 8.6 μm with a maximum signal-to-noise ratio of ∼7 × 103 in 10 s integration time, frequency-resolution of 160 kHz, and accuracy of less than 10 kHz.We present a mid-IR high-precision spectrometer capable of performing accurate Doppler-free measurements with absolute calibration of the optical axis and high signal-to-noise ratio. The system is based on a widely tunable mid-IR offset-free frequency comb and a Quantum-Cascade-Laser (QCL). The QCL emission frequency is offset locked to one of the comb teeth to provide absolute-frequency calibration, spectral-narrowing, and accurate fine frequency tuning. Both the comb repetition frequency and QCL-comb offset frequency can be modulated to provide, respectively, slow- and fast-frequency-calibrated scanning capabilities. The characterisation of the spectrometer is demonstrated by recording sub-Doppler saturated absorption features of the CHF3 molecule at around 8.6 μm with a maximum signal-to-noise ratio of ∼7 × 103 in 10 s integration time, frequency-resolution of 160 kHz, and accuracy of less than 10 kHz
MariX, an advanced MHz-class repetition rate X-ray source for linear regime time-resolved spectroscopy and photon scattering
The need of a fs-scale pulsed, high repetition rate, X-ray source for time-resolved fine analysis of matter
(spectroscopy and photon scattering) in the linear response regime is addressed by the conceptual design of a
facility called MariX (Multi-disciplinary Advanced Research Infrastructure for the generation and application of
X-rays) outperforming current X-ray sources for the declared scope. MariX is based on the original design of a
two-pass two-way superconducting linear electron accelerator, equipped with an arc compressor, to be operated
in CW mode (1 MHz). MariX provides FEL emission in the range 0.2–8 keV with 108 photons per pulse ideally
suited for photoelectric effect and inelastic X-ray scattering experiments. The accelerator complex includes an
early stage that supports an advanced inverse Compton source of very high-flux hard X-rays of energies up
to 180 keV that is well adapted for large area radiological imaging, realizing a broad science programme and
serving a multidisciplinary user community, covering fundamental science of matter and application to life
sciences, including health at preclinical and clinical level
Room-temperature Q-switched Tm:BaY(2)F(8) laser pumped by CW diode laser.
We report on the realization of CW diode-pumped Tm:BaY2F8 Q-switched laser at 1.93 mu m. Active Q-switching was obtained by means of an intracavity Pockels cell. A functional characterization of the laser performance is presented with particular attention to output energy, pulse duration, pulse stability, and wavelength tunability. Pulses with time duration as short as 170 ns were demonstrated at the minimum repetition rate of 5 Hz with an energy of 3.2 mJ (corresponding to a peak power of 19 kW). A wavelength tunability range from 1905 nm to 1990 nm has been observed. (c) 2006 Optical Society of America
The ADRICOSM Pilot Project: a coastal and river basin prediction system for the Adriatic Sea
The ADRICOSM project was launched in October 2001, and ended in March 2005, with the
main objective of demonstrating the feasibility of a near real time operational marine monitoring
and forecasting system at the shelf and coastal scales, with connections to river basin runoff and
coastal town sewer systems. The basic system consisted of an efficient network for the collection of
marine data such as in situ temperature and salinity profiles and satellite sea surface temperature, a
regional (AREG) and shelf scale modelling system, a data assimilation system and finally a coastal
scale modelling system. Every week AREG releases 7 day marine forecasts at 5 km horizontal
scales, which are used to nest other hydrodynamic models toward the coastal scale. Two shelf
models (ASHELF-1 and ASHELF-2) at a 1.5 km horizontal scale were nested in AREG in order to
simulate (and in the future to forecast) shelf scale oceanographic features. Another important aspect
of ADRICOSM was the integration of the Cetina river (Croatia) and urban sewage monitoring/
modelling (Split, Croatia) systems with the shelf marine model. This integrated model system was
used to simulate the dispersion of sewer discharges from the urban area in the coastal waters for
water management performance studies. ADRICOSM is one of the first integrated land and marine
waters operational oceanographic systems able to meet the urgent needs for reliable integrated
coastal forecasts for the effective management of marine areas
The Adriatic Basin forecasting system
A regional ocean forecasting system has been implemented in the framework of the ADRIatic
sea integrated COastal areaS and river basin Management system Pilot Project (ADRICOSM).
The system is composed of a 5 km horizontal resolution model and an observing system collecting
coastal and open ocean hydrological data. The numerical model is based on the Princeton Ocean
Model using a SMOLARKIEWICZ iterative advection scheme, interactive air-sea flux computation,
Po and other Adriatic rivers flow rates and is one-way nested to a general circulation model of
the Mediterranean Sea. In this study the data from the observing system are used only for model
validation. The results of the first operational year are shown and the model performance has been
assessed based on root mean square (RMS) criteria.Published169-184reserve
Raman soliton amplification by Tm-Ho:Fiber for high-efficiency Watt-level ultrashort pulses in the range 1.8-1.92 um; 2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC
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