Hydrogen Sulfide Detection in the Midinfrared Using a 3D-Printed Resonant Gas Cell

Figure 7

Photoacoustic signal when pump laser is tuned across the absorption line of H₂S at 1247.2 cm^-1 with different amplitude modulation frequencies. Black line: modulation frequency is 1.9 kHz. Red line: modulation frequency is 1.7 kHz. Blue line: modulation frequency is 2.1 kHz.