Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros

Base de dados
Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
Opt Express ; 30(25): 44908-44917, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36522904

RESUMO

In this work, the incubation effect on the laser ablation threshold of quartz, after multi-shot irradiation with femtosecond pulses at 1030-nm-wavelength with different repetition rates, was investigated. A strong decrease of the multi-pulse ablation threshold with the number of pulses N was found due to incubation. Moreover, the influence of the repetition rate was negligible in the investigated frequency range which went from 0.06 to 200 kHz. A saturation of the threshold fluence value was observed at number of pulses N > 100 which has been found to be well fitted by an exponential incubation model. Using such model, we estimated the single-pulse ablation threshold value and the incubation coefficient for quartz, which were found equal to Fth,1 = 6.23 ± 0.23 J/cm2 and k = 0.058 ± 0.004.

2.
Photoacoustics ; 28: 100401, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36105377

RESUMO

We report on a gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) able to detect multiple gas species for environmental monitoring applications, by exploiting a Vernier effect-based quantum cascade laser as the excitation source. The device emission spectrum consists of ten separated emission clusters covering the range from 2100 up to 2250 cm-1. Four clusters were selected to detect the absorption features of carbon monoxide (CO), nitrous oxide (N2O), carbon dioxide (CO2), and water vapor (H2O), respectively. The sensor was calibrated with certified concentrations of CO, N2O and CO2 in a wet nitrogen matrix. The H2O absorption feature was used to monitor the water vapor within the gas line during the calibration. Minimum detection limits of 6 ppb, 7 ppb, and 70 ppm were achieved for CO, N2O and CO2, respectively, at 100 ms of integration time. As proof of concept, the QEPAS sensor was tested by continuously sampling indoor laboratory air and monitoring the analytes concentrations.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA