Desenvolvimento de um laser pulsado com emissão em 1053 nm para utilização na técnica de "Cavity Ring-Down Spectroscopy" [thesis]

Fabio Cavalcanti
In this work, a pulsed and Q-switched laser resonator was developed using the double-beam mode-controlling technique. A Nd:LiYF 4 crystal with 0,8mol% of doping concentration was used to generate a giant pulse with duration of 5,5 ns (FWHM), 1,2 mJ of energy and 220 kW peak power for the Cavity Ring-Down Spectroscopy (CRDS) technique. The CRDS technique is used to measure absorption spectra for gases, liquids and solids. With the CRDS technique it is possible to measure losses with high degree
more » ... f accuracy, underscoring the sensitivity that is confirmed by the use of mirrors with high reflectivity. With this technique, the losses by reflection and scattering of transparent materials were evaluated. By calibrating the resonant cavity, it was possible to measure the losses in the samples with resolution of 0,045%, the maximum being reached by 1,73%. The calibration was possible because there was obtained to measure a decay time of approximately 20 μs with the empty cavity. Besides was obtained a method for determining the refractive index of transparent materials with accuracy of five decimals.
doi:10.11606/d.85.2014.tde-14102014-145230 fatcat:dtb7pmkknvdhdb2ypffewk7r44