The custom designed 15 kHz I-shape QTF is the optimal solution to couple quartz-enhanced photoacoustic spectroscopy (QEPAS) with light source characterized by large beam diameter due to its enlarged prong spacing.

Compared to the other custom designs, the 15 kHz QTF provide a large prong spacing to accomodate large beams for multiple applications, as well as a high quality factor.

Geometrical parameters as well as resonance properties of the custom QTF are reported in the following table. Additional information about the QTF and  can be found here.

Prong Spacing Quartz Crystal Thickness

 QTF full size

 Resonance Frequency (fundamental mode)

Quality Factor
1500 μm 250 μm 12.6 mm x 6 mm   15.8 kHz 25000