Affiliation:
1. Chinese Academy of Sciences
2. University and Politecnico of Bari, CNR-IFN
Abstract
In this Letter, a side-excitation light-induced thermoelastic spectroscopy (SE-LITES) technique was developed for trace gas detection. A novel, to the best of our knowledge, custom quartz tuning fork (QTF) was used as a transducer for photon detection by the thermoelastic effect. The mechanical stress distribution on the QTF surface was analyzed to identify the optimum thermoelastic excitation approach. The electrode film on the QTF surface also works as a partially reflective layer to obtain a long optical absorption path inside the QTF body. With the long optical absorption length and the inner face excitation of the QTF, the thermoelastic effect was greatly enhanced. With an optimized modulation depth, a signal-to-noise ratio (SNR) improvement of more than one order of magnitude was achieved, compared to traditional LITES.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Natural Science Foundation of Guangdong Province
Key-Area Research and Development Program of Guangdong Province
Special Project in Key Fields of the Higher Education Institutions of Guangdong Province
the Science and Technology Projects of Guangzhou
Foundation for Distinguished Young Talents in Higher Education of Guangdong
Chinese Aeronautical Establishment
Project of Guangzhou Industry Leading Talents
Fundamental Research Funds for the Central Universities
State Key Laboratory of Applied Optics
Subject
Atomic and Molecular Physics, and Optics