The PolySense team has just published a new article on Light: Science & Applications Journal (IF 19.4) reporting on an innovative technique of quartz-enhanced multiheterodyne resonant photoacoustic spectroscopy (QEMR-PAS), in which the beat frequency response from a dual comb is frequency down-converted into the audio frequency domain. In this way, gas molecules act as an optical-acoustic converter through the photoacoustic effect, generating heterodyne sound waves. Unlike conventional DCS, where the light wave is detected by awavelength dependent photoreceiver, QEMR-PAS employs a quartz tuning fork (QTF) as a high-Q sound transducer and works in conjunction with a phase-sensitive detector to extract the resonant sound component from the multiple
heterodyne acoustic tones, resulting in a straightforward and low-cost hardware configuration. This novel QEMRPAS technique enables wavelength-independent DCS detection for gas sensing, providing an unprecedented dynamic range of 63 dB, a remarkable spectral resolution of 43 MHz (or ~0.3 pm), and a prominent noise equivalent absorption of 5.99 × 10-6 cm-1·Hz-1/2.
The following link provides access to the article:
http://polysense.poliba.it/wp-content/uploads/2024/03/QEPAS-dual-comb-Lights-2024.pdf
