Dual-band light-induced thermoelastic spectroscopy utilizing an antiresonant hollow-core fiber-based gas absorption cell

In this paper, dual-band gas detection using a combination of the light-induced thermoelastic spectroscopy (LITES) and an antiresonant hollow-core fiber-based (ARHCF) gas absorption cell is demonstrated. The broad wavelength operation capability of a standard 32 kHz quartz tuning fork and the self-developed fiber-based gas absorption cell was exploited to demonstrate quasi-simultaneous detection of N 2 O and CO 2 , at 4570 nm (2188.2 cm −1 ) and 2006 nm (4985.9 cm −1 ), respectively. The signal analysis was based on the wavelength modulation spectroscopy technique, allowing to achieve a noise equivalent absorption coefficient (NEA) of 8.6 × 10 –7 cm −1 and 1.7 × 10 –6 cm −1 for N 2 O and CO 2 , respectively. The results indicate that the combination of ARHCFs with the LITES method is well suited for the design of broadband gas detectors and show remarkable potential in the fabrication of miniaturized, versatile and relatively inexpensive gas sensors operating over a wide spectral range, thus allowing multigas detection.