A Dual-component Detection Photoacoustic Spectroscopy Sensor Based on YY-type Photoacoustic Cell

In this paper, we present a dual-component detection photoacoustic spectroscopy (PAS) sensor based on a YY-type photoacoustic cell (PAC), which is designed for the simultaneous detection of two trace gases. As the core component of the detection system, the YY-type PAC is designed by utilizing 3D printing technology. It incorporates two cylindrical resonators of different sizes and a truncated cone-shaped buffer chamber. The two resonators are arranged in parallel and connected to the microphone via a dedicated sound channel. Each resonator has distinct acoustic and optical properties, enabling it to generate photoacoustic (PA) signals independently. A single microphone is positioned between the two resonators in the YY-type PAC, allowing for the simultaneous measurement of PA signals from both resonators. Additionally, we employ the thermos viscous acoustics (TVA) module of COMSOL Multiphysics software to simulate the designed PAC, optimizing its parameters for improved performance. The high-performance YY-type PAC is designed with resonant frequencies of 3.9 kHz and 5 kHz. In our dual-component PAS sensor, two distributed feedback (DFB) lasers with wavelengths of 1653 nm and 1531.12 nm are employed alongside a lock-in amplifier and a YY-type PAC to enable the high-sensitivity detection of methane (CH
₄
) and acetylene (C
₂
H
₂
) gases. This setup achieves minimum detection limits (MDL) of 0.52 ppm for CH
₄
and 1.57 ppm for C
₂
H
₂
, respectively. The YY-type PAC introduced in this study integrates the benefits of simultaneous dual-component detection, ease of integration, low gas consumption, and miniaturization.