Folded-optics-based quartz-enhanced photoacoustic and photothermal hybrid spectroscopy (FO-QEPA-PTS) is reported for the first time. In FO-QEPA-PTS, the detection of the photoacoustic and photothermal hybrid signal is achieved through the use of a custom quartz tuning fork (QTF), thereby mitigating the issue of resonant frequency mismatch typically encountered in quartz-enhanced photoacoustic-photothermal spectroscopy employing multiple QTFs. A multi-laser beam, created by a multi-pass cell (MPC) with a designed single-line spot pattern, partially strikes the inner edge of the QTF and partially passes through the prong of the QTF, thereby generating photoacoustic and photothermal hybrid signals. To assess the performance of FO-QEPA-PTS, 1 % acetylene is selected as the analyte gas and the 2f signals produced by the photoacoustic, the photothermal, and their hybrid effects are measured. Comparative analysis against QEPAS and QEPTS reveals signal gain factors of ∼ 79 and ∼ 14, respectively, when these laser beams created by MPC excite the QTF operating at fundamental resonance mode in phase. In the FO-QEPA-PTS signal, the proportions of the photoacoustic and the photothermal effects induced by the multiple beams are ∼7 % and 93 %, respectively.

首次报道了基于折叠光学的石英增强光声光热混合光谱（FO-QEPA-PTS）。在 FO-QEPA-PTS 中，光声和光热混合信号的检测是通过使用定制石英音叉 (QTF) 实现的，从而缓解了石英增强光声光热光谱中通常遇到的共振频率失配问题多个 QTF。由具有设计的单线光斑图案的多通道单元 (MPC) 创建的多激光束部分撞击 QTF 的内边缘并部分穿过 QTF 的尖头，从而生成光声和光热混合信号。为了评估 FO-QEPA-PTS 的性能，选择 1% 乙炔作为分析气体，并测量光声、光热及其混合效应产生的2 f信号。与 QEPAS 和 QEPTS 的比较分析表明，当 MPC 产生的这些激光束激发同相以基本谐振模式运行的 QTF 时，信号增益因子分别为 79 和 14。在 FO-QEPA-PTS 信号中，多光束引起的光声效应和光热效应的比例分别为 ∼7% 和 93%。