Geometrical parameters of micro-resonator for a quartz enhanced photoacoustic spectroscopy sensor are optimized to perform sensitive and background-free spectroscopic measurements using mid-IR quantum cascade laser (QCL) excitation sources. Such an optimized configuration is applied to nitric oxide (NO) detection at 1900.08 cm−1 (5.26 μm) with a widely tunable, mode-hop-free external cavity QCL. For a selected NO absorption line that is free from H2O and CO2 interference, a NO detection sensitivity of 4.9 parts per billion by volume is achieved with a 1-s averaging time and 66 mW optical excitation power. This NO detection limit is determined at an optimal gas pressure of 210 Torr and 2.5% of water vapor concentration. Water is added to the analyzed mixture in order to improve the NO vibrational-translational relaxation process.

Ppb-level detection of nitric oxide using an external cavity quantum cascade laser based QEPAS sensor

SPAGNOLO, Vincenzo Luigi;
2011

Abstract

Geometrical parameters of micro-resonator for a quartz enhanced photoacoustic spectroscopy sensor are optimized to perform sensitive and background-free spectroscopic measurements using mid-IR quantum cascade laser (QCL) excitation sources. Such an optimized configuration is applied to nitric oxide (NO) detection at 1900.08 cm−1 (5.26 μm) with a widely tunable, mode-hop-free external cavity QCL. For a selected NO absorption line that is free from H2O and CO2 interference, a NO detection sensitivity of 4.9 parts per billion by volume is achieved with a 1-s averaging time and 66 mW optical excitation power. This NO detection limit is determined at an optimal gas pressure of 210 Torr and 2.5% of water vapor concentration. Water is added to the analyzed mixture in order to improve the NO vibrational-translational relaxation process.
File in questo prodotto:
File Dimensione Formato  
54_Optic Express NO_2011.pdf

accesso aperto

Tipologia: Versione editoriale
Licenza: Tutti i diritti riservati
Dimensione 1.22 MB
Formato Adobe PDF
1.22 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11589/10078
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • Scopus 118
  • ???jsp.display-item.citation.isi??? 112
social impact