TY - GEN
T1 - Real time ammonia detection in exhaled human breath using a distributed feedback quantum cascade laser based sensor
AU - Lewicki, Rafał
AU - Kosterev, Anatoliy A.
AU - Thomazy, David M.
AU - Risby, Terence H.
AU - Solga, Steven
AU - Schwartz, Timothy B.
AU - Tittel, Frank K.
PY - 2011
Y1 - 2011
N2 - A continuous wave, thermoelectrically cooled, distributed feedback quantum cascade laser (DFB-QCL) based sensor platform for the quantitative detection of ammonia (NH3) concentrations present in exhaled human breath is reported. The NH3 concentration measurements are performed with a 2f wavelength modulation quartz enhanced photoacoustic spectroscopy (QEPAS) technique, which is very well suited for real time breath analysis, due to the fast gas exchange inside a compact QEPAS gas cell. An air-cooled DFB-QCL was designed to target the interference-free NH3 absorption line located at 967.35 cm-1 (λ∼10.34 μm). The laser is operated at 17.5 °C, emitting ∼ 24 mW of optical power at the selected wavelength. A 1σ minimum detectable concentration of ammonia for the line-locked NH3 sensor is ∼ 6 ppb with 1 sec time resolution. The NH3 sensor, packaged in a 12"x14"x10" housing, is currently installed at a medical breath research center in Bethlehem, PA and tested as an instrument for non-invasive verification of liver and kidney disorders based on human breath samples.
AB - A continuous wave, thermoelectrically cooled, distributed feedback quantum cascade laser (DFB-QCL) based sensor platform for the quantitative detection of ammonia (NH3) concentrations present in exhaled human breath is reported. The NH3 concentration measurements are performed with a 2f wavelength modulation quartz enhanced photoacoustic spectroscopy (QEPAS) technique, which is very well suited for real time breath analysis, due to the fast gas exchange inside a compact QEPAS gas cell. An air-cooled DFB-QCL was designed to target the interference-free NH3 absorption line located at 967.35 cm-1 (λ∼10.34 μm). The laser is operated at 17.5 °C, emitting ∼ 24 mW of optical power at the selected wavelength. A 1σ minimum detectable concentration of ammonia for the line-locked NH3 sensor is ∼ 6 ppb with 1 sec time resolution. The NH3 sensor, packaged in a 12"x14"x10" housing, is currently installed at a medical breath research center in Bethlehem, PA and tested as an instrument for non-invasive verification of liver and kidney disorders based on human breath samples.
KW - Quartz enhanced photoacoustic spectroscopy
KW - distributed feedback quantum cascade laser
KW - trace gas ammonia detection
KW - wavelength modulation
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U2 - 10.1117/12.874887
DO - 10.1117/12.874887
M3 - Conference contribution
AN - SCOPUS:79955757488
SN - 9780819484826
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Quantum Sensing and Nanophotonic Devices VIII
T2 - Quantum Sensing and Nanophotonic Devices VIII
Y2 - 23 January 2011 through 27 January 2011
ER -