Photoacoustic spectroscopy-based ppb-level multi-gas sensor using symmetric multi-resonant cavity photoacoustic cell

Tailin Li; Chaotan Sima; Yan Ai; Chen Tong; Jinbiao Zhao; Zikai Zhao; Ping Lu

doi:10.1016/j.pacs.2023.100526

Photoacoustic spectroscopy-based ppb-level multi-gas sensor using symmetric multi-resonant cavity photoacoustic cell

Photoacoustics. 2023 Jul 1:32:100526. doi: 10.1016/j.pacs.2023.100526. eCollection 2023 Aug.

Authors

Tailin Li¹, Chaotan Sima¹, Yan Ai¹, Chen Tong¹, Jinbiao Zhao¹, Zikai Zhao², Ping Lu¹

Affiliations

¹ Next Generation Internet Access National Engineering Research Center, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
² International Business Division, Accelink Technologies Co., Ltd, Wuhan 430205, China.

Abstract

In this paper, we propose and experimentally demonstrate a symmetric multi-resonant cavity photoacoustic cell (MR-PAC) with dual microphones detection, based on multi-resonator photoacoustic spectroscopy (MR-PAS). The designed photoacoustic cell contains three interconnected acoustic resonators to facilitate simultaneous control of three lasers for multi-gas sensing. Two microphones are symmetrically located at both sides of photoacoustic cell to implement two-point detection. The length of acoustic resonator is about 50 mm to minimize the photoacoustic cell, and the resonant frequency is around 3000 Hz. Feasibility and performance of the MR-PAC was demonstrated by simultaneous detection of C₂H₂, NO and CF₄ using a near infrared diode laser and two mid infrared quantum cascade lasers. The minimum detection limits (MDLs) of C₂H₂, NO and CF₄ are 480 ppb, 260 ppb and 0.57 ppb respectively with a 1 s integration time at normal atmospheric pressure. This minimized MR-PAS system is promising for the portable multi-gas sensing.

Keywords: Gas sensing; Multi-resonator; Photoacoustic Cell; Photoacoustic Spectroscopy.