Search results for "tunable diode laser"

Argon broadening of the 13CO R(0) and R(7) transitions in the fundamental band at temperatures between 80 and 297K: comparison between experiment and…

2003

We present measurements of Ar-broadening parameters for the R(0) and R(7) lines in the fundamental band of13CO at eight temperatures from 80 to 297 K. The broadening parameters are determined by simultaneous least-squares fitting of spectra recorded using a frequency stabilized diode laser spectrometer. The comparison of the broadening parameter values for R(7) derived at room temperature and different pressures from different line profiles shows that an empirical line profile, which takes into account narrowing effects (Dicke narrowing and absorber speed dependence) but neglects any correlation between collisions, is able to describe the observed lines with constant values of the narrowing…

VOLCANIC CO2 FLUX MEASUREMENTS BY TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY

2013

Introduction In the last decades, the use of near-infrared room-temperature diode lasers for gas sensing has grown significantly. The use of these devices, for instance in combination with optical fibers, is particularly convenient for volcanic monitoring applications [1,2]. Here, we report on the first results of the application of an open-path infrared tunable laser-based at Campi Flegrei (Southern Italy). Such Diode-laser-based measurements were performed, during two field campaigns (october 2012, and january 2013), in the attempt to obtain novel information on the current degassing unrest of Solfatara and Pisciarelli fumarolic fields. Results and Discussion At each site, we used an ad-h…

Tunable dual-wavelength thulium-doped fiber laser in the range from 2067 to 2073.5 nm

2017

A tunable dual-wavelength lineal cavity Tm-doped fiber laser is presented. The generation of the laser lines is based on the use of cascaded fiber Bragg gratings and a Hi-Bi fiber optic loop mirror.

4W continuous-wave narrow-linewidth tunable solid-state laser source at 546nm by externally frequency doubling a ytterbium-doped single-mode fiber la…

2009

A high-power continuous-wave coherent light source at 545.5nm is described. We use 8.3W from a solid-state ytterbium-doped single-mode fiber oscillator/amplifier system as input into an external frequency doubling stage. This system produces up to 4.1 W of stable green single-frequency laser radiation. We characterize the light source by performing absorption spectroscopy on iodine across the full tuning range of the fiber laser and saturation spectroscopy on one strong iodine line of the doppler-broadened spectrum.

Measurement of the transition dipole moment of silane 28SiH4 by diode laser spectroscopy

1992

Abstract A tunable diode laser IR spectrometer which is being used in various molecular spectroscopy experiments is described. Absorption spectra observed in the ( ν 1 , ν 3 ) dyad of silane 28 SiH 4 yield estimates of two parameters of the dipole moment operator responsible for absorbance in this region.

Real-time measurements of Volcanic Gases based by Infrared Spectroscopy

2014

Near-infrared Tunable Diode Lasers have recently found increased usage in atmospheric chemistry and air monitoring research, but applications in Volcanology are still limited to a few examples. The Tunable Diode Laser Spectroscopy technique (TDLS) relies on measuring the absorbance at specific wavelengths due to the absorption of IR radiation by a target gas. Here, we report on the application of the GasFinder 2.0, a commercial infrared laser-receiver unit operating in the 1.3-1.7 m wavelength range, to measuring CO2 concentrations and fluxes in volcanic gas emissions. Our field tests were conducted at Campi Flegrei volcano (near Pozzuoli, Southern Italy), where the GasFinder was used (duri…

Frequency-modulation spectroscopy with blue diode lasers

2000

Frequency-modulation spectroscopy provides ultrasensitive absorption measurements. The technique is especially adaptable to diode lasers, which can be modulated easily, and has been used extensively in the near-infrared and infrared spectral regions. The availability of blue diode lasers now means that the accessible wavelength region can be increased. We successfully demonstrate wavelength-modulation spectroscopy and two-tone frequency-modulation spectroscopy for the weak second resonance line of potassium at 404.8 nm and for the transition at 405.8 nm in lead, starting from the thermally populated 6p(2) P-3(2) metastable level, information on the modulation parameters is obtained with a f…

Subpicosecond Laser Spectroscopy of Blue-Light-Induced Absorption in KNbO3 and LiNbO3

2000

Pulses of 427-nm light from am amplified Ti:sapphire frequency-doubled laser are absorbed in two-photon band-gap excitations of KNbO3 and LiNbO3. Induced absorption spectra measured in the visible and recently extended in the infrared have been recorded as a function of delay from 0 to 250 ps after two-photon blue excitation. Samples include stoichiometric as well as congruent LiNbO3. Comparison is made to transient absorption in the nanosecond and longer time range induced by electron pulses of~10 ns width and 270 keV energy. Parts of the absorption can be attributed to bound and free polarons, including the intrinsic electron polaron.

Violet Diode Laser in Time-Resolved Stored-Ion Spectroscopy

2004

Lifetime measurements of the metastable 3d D-2(3/2) level in singly charged calcium were performed using the newly developed violet diode laser operated in an external cavity arrangement. The laser was employed on stored ions at the CRYRING facility to optically pump the resonance line at 397 nm. In combination with laser probing at 866 nm this detection scheme gave the possibility to record the lifetime of this level. which has a radiative lifetime of about 1 s.

REAL-TIME MEASUREMENT OF VOLCANIC GASES BASED ON INFRARED SPECTROSCOPY

The interpretation of volcanic gas datasets offers key information to build/validate geological models relevant to a variety of volcanic processes and behaviours, including eruptions. Major efforts have therefore been spent in recent years to improve our ability to measure volcanic gas compositions and fluxes. In the last decades, near-infrared room-temperature diode lasers, though in an experimental phase, are finding applications in volcanic gas studies. In this PhD dissertation, I use the GasFinder 2.0, a commercial tunable diode infrared laser transmitter-receiver unit, operating in the 1.3-1.7 m wavelength range, in the attempt to measure CO2 mixing ratios and fluxes in volcanic gas e…