Wavelength-Tunable Quantum Absorption Spectroscopy in the Broadband Midinfrared Region

Abstract

Infrared quantum absorption spectroscopy (IRQAS) enables the estimation of a sample's optical properties in the infrared region, using only a visible light source and detectors, which is technologically favorable. So far, spectral coverage of IRQAS systems has been limited to less than 1 \textmu{}m. This work reports a wavelength-tunable IRQAS system and an efficient measurement scheme to achieve broadband spectroscopy in a short acquisition time. The successful demonstration of rapid spectral measurement over a wide midinfrared window (1.9--5.2 \textmu{}m) exhibits the great potential of this technique and paves the way for the use of IRQAS in real-world applications.