We report on absolute measurements of saturatedabsorption line-center frequencies of room-temperature trifluoromethane using a quantum cascade laser at 8.6 μm and the frequency modulation spectroscopy method. Absolute calibration of the laser frequency is obtained by direct comparison with a mid-infrared optical frequency comb synthesizer referenced to a radio-frequency Rb standard. Several sub-Doppler transitions falling in the υ5 vibrational band are investigated at around 1158.9 cm−1 with a fractional frequency precision of 8.6 · 10−12 at 1-s integration time, limited by the Rb-clock stability. The demonstrated frequency uncertainty of 6.6 · 10−11 is mainly limited by the reproducibility of the frequency measurements.
Absolute frequency measurements of CHF3 Doppler-free ro-vibrational transitions at 8.6 micron
Fasci, Eugenio;GIANFRANI, Livio;CASTRILLO, Antonio;
2017
Abstract
We report on absolute measurements of saturatedabsorption line-center frequencies of room-temperature trifluoromethane using a quantum cascade laser at 8.6 μm and the frequency modulation spectroscopy method. Absolute calibration of the laser frequency is obtained by direct comparison with a mid-infrared optical frequency comb synthesizer referenced to a radio-frequency Rb standard. Several sub-Doppler transitions falling in the υ5 vibrational band are investigated at around 1158.9 cm−1 with a fractional frequency precision of 8.6 · 10−12 at 1-s integration time, limited by the Rb-clock stability. The demonstrated frequency uncertainty of 6.6 · 10−11 is mainly limited by the reproducibility of the frequency measurements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
