Opt Lett. 2022 Sep 1;47(17):4556-4559. doi: 10.1364/OL.464334.
In this Letter, clamp-type quartz tuning fork enhanced photoacoustic spectroscopy (Clamp-type QEPAS) is proposed and realized through the design, realization, and testing of clamp-type quartz tuning forks (QTFs) for photoacoustic gas sensing. The clamp-type QTF provides a wavefront-shaped aperture with a diameter up to 1 mm, while keeping Q factors > 10. This novel, to the best of our knowledge, design results in a more than ten times increase in the area available for laser beam focusing for the QEPAS technique with respect to a standard QTF. The wavefront-shaped clamp-type prongs effectively improve the acoustic wave coupling efficiency. The possibility to implement a micro-resonator system for clamp-type QTF is also investigated. A signal-to-noise enhancement of ∼30 times has been obtained with a single-tube acoustic micro resonator length of 8 mm, ∼20% shorter than the dual-tube micro-resonator employed in a conventional QEPAS system.
在这封信件中，我们提出并实现了通过设计、实现和测试夹式石英音叉（Clamp-type QTF）用于光声气体传感的夹式石英调谐叉增强光声光谱（Clamp-type QEPAS）。夹式 QTF 提供了一个直径可达 1 毫米的波前形孔径，同时保持 Q 因子>10。这种新颖的设计，据我们所知，与标准 QTF 相比，QEPAS 技术的激光束聚焦面积增加了十倍以上。波前形夹式叉有效地提高了声波耦合效率。还研究了实现夹式 QTF 微谐振器系统的可能性。采用单管声微谐振器长度为 8 毫米，与传统 QEPAS 系统中使用的双管微谐振器相比，长度缩短了约 20%，获得了约 30 倍的信噪比增强。
