Highly Sensitive and Fast Hydrogen Detection Based on Light-Induced Thermoelastic Spectroscopy  

作　　者：Yufei Ma Tiantian Liang Shunda Qiao Xiaonan Liu Ziting Lang 

机构地区：[1]National Key Laboratory of Science and Technology on Tunable Laser,Harbin Institute of Technology,Harbin 150001,China

出　　处：《Ultrafast Science》2023年第3期9-17,共9页超快科学（英文）

基　　金：the National Natural Science Foundation of China(grant nos.62275065,62022032,61875047,and 61505041);Fundamental Research Funds for the Central Universities.

摘　　要：As a new energy source,hydrogen(H_(2))detection is a hot topic in recent years.Because of the weak absorption characteristic,laser spectroscopy-based H_(2)detection is challenging.In this paper,a highly sensitive H_(2)sensor based on light-induced thermoelastic spectroscopy(LITES)technique is demonstrated for the first time.A continuous-wave,distributed feedback diode laser with emission in the 2.1μm region was adopted as the excitation source to target the strongest H_(2)absorption line of 4,712.90 cm^(−1).A Herriott multipass cell with an optical length of 10.1 m was chosen to further improve the H_(2)absorption.With the feature of processing the raw input data without data preprocessing and extracting the desired features automatically,the robust shallow neural network(SNN)fitting algorithm was brought in to denoise the sensor.For the LITES-based H_(2)sensor,the concentration response was tested,and an excellent linear response to H_(2)concentration levels was achieved.A minimum detection limit(MDL)of~80 ppm was obtained.On the basis of implementation of the H_(2)-LITES sensor,a heterodyne H_(2)-LITES sensor was further constructed to realize a fast measurement of resonance frequency of quartz tuning fork and H_(2)concentration simultaneously.The resonance frequency can be retrieved in several hundred milliseconds with the measurement accuracy of±0.2 Hz,and the result of 30,713.76 Hz is exactly same as the experimentally determined value of 30,713.69 Hz.After the SNN algorithm was applied,an MDL of~45 ppm was achieved for this heterodyne H_(2)-LITES sensor.

关 键 词：tuning ABSORPTION HIGHLY 

分 类 号：TN24[电子电信—物理电子学]