Search results for "tunable laser"
showing 10 items of 41 documents
Resonance Ionization Laser Ion Source - Off-line tests at TRIUMF
2004
Resonance ionization laser ion sources (RILIS) developed into the most powerful tool for radioactive ion beam production at on-line facilities, as they provide a selective ionization process with inherent suppression of unwanted isobaric contaminations at the ion source. While typical tunable laser systems for these applications are based on dye lasers, we developed an all solid state laser system which consists of three pulsed titanium:sapphire (ti:sa) lasers pumped by a single high repetition rate Nd:YAG laser. Each ti:sa laser provides up to 2.5 W average output power at 12 kHz repetition rate in the wavelength region of 700-950 nm with optional frequency doubling in BBO crystals. This l…
Ion storage technique for very long living states: The decay rate of the 5D 3/2 state of Ba II
1979
The metastable 5D 3/2 state of Ba+ is used to demonstrate the possibility of the ion storage technique for the measurement of extremely long lived states. The ions are confined in a r.f. quadrupole trap and excited by a strong pulsed tunable dye laser to the 6P 1/2 state which partially decays into the 5D 3/2 state. Sampling of the time development of the ground state population leads to the determination of the 5D 3/2 decay rate. Using He as a buffer gas at a pressure of about 10−6 mbar to initially store the ions, varying the gas density and extrapolating to zero pressure, we find for the lifetime $$\tau _{D_{3/2} } = 17.5 \pm 4s$$ .
29SiH4 and 30SiH4: Dipole moment parameters of the dyad from Stark effect observations with laser sidebands
1990
Abstract The linear Stark effect within the ν 2 ν 4 dyad of 29SiH4 and 30SiH4 has been investigated by applying the infrared sideband technique at microwave modulation frequencies. Two vibration-induced dipole moment parameters have been measured for each isotopomer on natural abundance samples.
Statistical description of soliton clustering in fiber lasers with slow-gain dynamics
2014
We demonstrate theoretically that the dynamic clustering of solitons observed in a variety of experiments are due to the initial phase and position of interacting solitons with the slow gain dynamics of the fiber laser.
Tunable defects in colloidal photonic crystals
2006
We present a bottom-up approach for the construction of tunable functional defects in colloidal photonic crystals (CPCs). These structures incorporate polyelectrolyte multilayer (PEM) planar defects embedded in silica CPCs through a combination of evaporation induced self-assembly and microcontact transfer printing. We show how the enormous chemical diversity inherent to PEMs can be harnessed to create chemically active defect structures responsive to solvent vapor pressures, light, temperature as well as redox cycling. A sharp transmission state within the photonic stopband, induced by the PEM defect, can be precisely, reproducibly and in some cases reversibly tuned by these external stimu…
Crystal growth and refined Sellmeier equations over the complete transparency range of RbTiOPO4
2003
Abstract The phase-matching directions sum- and difference-frequency generations are measured in the principal planes of RbTiOPO 4 crystals grown from a halide flux. The use of crystals with a cylindrical shape and of a tunable laser source allows us to perform accurate measurements over the complete transparency range of that material, and to determine a refined set of Sellmeier equations valid for any phase-matched interaction in that crystal.
Finely tunable laser based on a bulk silicon wafer for gas sensing applications
2016
In this work a very simple continuously tunable laser based on an erbium ring cavity and a silicon wafer is presented. This laser can be tuned with very fine steps, which is a compulsory characteristic for gas sensing applications. Moreover the laser is free of mode hopping within a spectral range sufficiently wide to match one of the ro-vibrational lines of a target molecule. Here the proposed laser reached, at ∼1530 nm, a continuous tuning range of around 950 pm (>100 GHz) before mode hopping occurred, when a silicon wafer of 355 μm thickness was used. Additionally, the laser can be finely tuned with small tuning steps of <12 pm, achieving a resolution of 84.6 pm °C-1 and by using a therm…
Self-limiting and complete oxidation of silicon nanostructures produced by laser ablation in water
2016
Oxidized Silicon nanomaterials produced by 1064 nm pulsed laser ablation in deionized water are investigated. High-resolution transmission electron microscopy coupled with energy dispersive X-ray spectroscopy allows to characterize the structural and chemical properties at a sub-nanometric scale. This analysis clarifies that laser ablation induces both self-limiting and complete oxidation processes which produce polycrystalline Si surrounded by a layer of SiO2 and amorphous fully oxidized SiO2, respectively. These nanostructures exhibit a composite luminescence spectrum which is investigated by time-resolved spectroscopy with a tunable laser excitation. The origin of the observed luminescen…
Tunable diode laser measurements of hydrothermal/volcanic CO&lt;sub&gt;2&lt;/sub&gt; and implications for the global CO&lt;sub&am…
2014
Abstract. Quantifying the CO2 flux sustained by low-temperature fumarolic fields in hydrothermal/volcanic environments has remained a challenge, to date. Here, we explored the potential of a commercial infrared tunable laser unit for quantifying such fumarolic volcanic/hydrothermal CO2 fluxes. Our field tests were conducted between April 2013 and March 2014 at Nea Kameni (Santorini, Greece), Hekla and Krýsuvík (Iceland) and Vulcano (Aeolian Islands, Italy). At these sites, the tunable laser was used to measure the path-integrated CO2 mixing ratios along cross sections of the fumaroles' atmospheric plumes. By using a tomographic post-processing routine, we then obtained, for each manifestati…
Bright Visible Luminescence in Silica Nanoparticles
2011
International audience; We demonstrate that a porous film of silica nanoparticles emits a bright visible luminescence associated with defects stabilized by oxygen chemisorption at oxygen deficient center sites. Time-resolved spectra excited by a tunable laser allow us to distinguish the luminescence at 1.99 eV, characteristic of the nonbridging oxygen hole center (NBOHC) (Si-O)3 Si-O*, and a fast and a slow emission: the first (lifetime τ ≈ 25 ns) is peaked at 2.27 eV with an excitation spectrum centered at 5.5 eV; the second (τ ≈ 7.5 μs) is peaked at 2.41 eV and is excited around 3.2 and 5.2 eV. Reaction in an air atmosphere leads to the disappearance of the NBOHC luminescence and of the …