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Qiao S, He Y, Sun H, Patimisco P, Sampaolo A, Spagnolo V, Ma Y. Ultra-highly sensitive dual gases detection based on photoacoustic spectroscopy by exploiting a long-wave, high-power, wide-tunable, single-longitudinal-mode solid-state laser. LIGHT, SCIENCE & APPLICATIONS 2024; 13:100. [PMID: 38693126 PMCID: PMC11063167 DOI: 10.1038/s41377-024-01459-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 04/11/2024] [Accepted: 04/14/2024] [Indexed: 05/03/2024]
Abstract
Photoacoustic spectroscopy (PAS) as a highly sensitive and selective trace gas detection technique has extremely broad application in many fields. However, the laser sources currently used in PAS limit the sensing performance. Compared to diode laser and quantum cascade laser, the solid-state laser has the merits of high optical power, excellent beam quality, and wide tuning range. Here we present a long-wave, high-power, wide-tunable, single-longitudinal-mode solid-state laser used as light source in a PAS sensor for trace gas detection. The self-built solid-state laser had an emission wavelength of ~2 μm with Tm:YAP crystal as the gain material, with an excellent wavelength and optical power stability as well as a high beam quality. The wide wavelength tuning range of 9.44 nm covers the absorption spectra of water and ammonia, with a maximum optical power of ~130 mW, allowing dual gas detection with a single laser source. The solid-state laser was used as light source in three different photoacoustic detection techniques: standard PAS with microphone, and external- and intra-cavity quartz-enhanced photoacoustic spectroscopy (QEPAS), proving that solid-state laser is an attractive excitation source in photoacoustic spectroscopy.
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Affiliation(s)
- Shunda Qiao
- National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin, China
| | - Ying He
- National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin, China
| | - Haiyue Sun
- National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin, China
| | - Pietro Patimisco
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola, Bari, Italy
| | - Angelo Sampaolo
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola, Bari, Italy
| | - Vincenzo Spagnolo
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola, Bari, Italy
| | - Yufei Ma
- National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin, China.
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Zhao X, Guo M, Cui D, Li C, Qi H, Chen K, Ma F, Huang J, Zhang G, Zhao J. Multi-pass Differential Photoacoustic Sensor for Real-Time Measurement of SF 6 Decomposition Component H 2S at the ppb Level. Anal Chem 2023; 95:8214-8222. [PMID: 37192501 DOI: 10.1021/acs.analchem.3c00003] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We designed and implemented a photoacoustic (PA) sensor for H2S detection in SF6 background gas based on a multi-pass differential photoacoustic cell (MDPC) and a near-infrared distributed feedback (DFB) laser. In the MDPC apparatus, two resonators with identical geometric parameters were vertically and symmetrically embedded. The differential processing algorithm of two phase-reversed signals realized the effective enhancement of the PA signal and suppressed the flow noise in the dynamic sampling process. In addition, the λ/4 buffer chamber in the MDPC was utilized as a muffler to further reduce the flow noise and realize the dynamic detection of H2S. The collimated excitation light was reflected 30 times in a multi-pass structure constituted of two gold-plated concave mirrors, and an absorption path length of 4.92 m was achieved. Due to the high gas density of SF6, the relationship between the signal-to-noise ratio (SNR) and the gas flow was different between SF6 and N2 background gases. The maximum flow rate of the characteristic gas components detected in the SF6 background is 150 standard cubic centimeters per minute (SCCM), which is lower than 350 SCCM in N2. The linearity property was analyzed, and the results show that the sensitivity of the sensor to H2S in the SF6 background was 27.3 μV/ppm. With the structure, parameters, temperature, gas flow, and natural frequency of the MDPC been optimized, a minimum detection limit (MDL) of 11 ppb was reached with an averaging time of 1000 s, which furnished an effective preventive implement for the safe operation of gas insulation equipment.
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Affiliation(s)
- Xinyu Zhao
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Min Guo
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Dongyu Cui
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Chenxi Li
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Hongchao Qi
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Ke Chen
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Fengxiang Ma
- Electric Power Research Institute, Net Anhui Electric Power Co., Ltd, Hefei, Anhui 230601, China
| | - Jiayu Huang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Guangyin Zhang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Jikuan Zhao
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China
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He Q, Zhu W, Lv H, Wen X, Zheng Z, Wang J, Li M. Multi-MEMS-microphone schemes in a miniature photoacoustic cell for acetylene trace gas measurement. APPLIED OPTICS 2023; 62:1647-1653. [PMID: 36821330 DOI: 10.1364/ao.481824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/14/2023] [Indexed: 06/18/2023]
Abstract
Dissolved gas analysis is a strong tool for online health monitoring of electrical power equipment. The industry's large-scale deployment of photoacoustic (PA) sensors is still constrained by cost and sensitivity, despite the great accuracy achieved with a mid-infrared light source or optical sensors. We provide a low-cost PA sensor for ppb-level trace gas sensing based on a near-infrared distributed feedback laser source, miniature gas cell, and multiple microelectromechanical system (MEMS) microphones. Five multi-MEMS-microphones schemes are modeled. The simulation indicates that the sensor, including two MEMS microphones in the center of the resonator, is the most cost-efficient option. The experiments that present this scheme can be realized easily by modifying a traditional single microphone PA cell and with ppb-level sensitivity.
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Guo M, Zhao X, Chen K, Cui D, Zhang G, Li C, Gong Z, Yu Q. Multi-mechanism collaboration enhanced photoacoustic analyzer for trace H 2S detection. PHOTOACOUSTICS 2023; 29:100449. [PMID: 36654963 PMCID: PMC9841283 DOI: 10.1016/j.pacs.2023.100449] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 01/01/2023] [Accepted: 01/03/2023] [Indexed: 05/25/2023]
Abstract
To realize the real-time highly sensitive detection of SF6 decomposition product H2S, a multi-mechanism collaboration enhancement photoacoustic spectroscopy analyzer (MCEPA) based on acoustic resonance enhancement, cantilever enhancement and excitation light enhancement is proposed. An SF6 background gas-induced photoacoustic cell (PAC) was used for acoustic resonance (AR) enhancement of the photoacoustic signals. A fiber-optic acoustic sensor based on a silicon cantilever is optimized and fabricated. The narrow-band acoustic signal enhancement based on cantilever mechanical resonance (MR) is realized in the optimal working frequency band of the PAC. A fiber-coupled DFB cascaded an Erbium-doped fiber amplifier (EDFA) realized the light power enhancement (LPE) of the photoacoustic signals excitation source. Experimental results show that the MR of the fiber-optic silicon cantilever acoustic sensor (FSCAS) is matched with the AR of the PAC and combined with the LPE, which realizes the multi-mechanism collaboration enhancement of weak photoacoustic signals. The Allan-Werle deviation evaluation showed that the minimum detection limit of H2S in the SF6 background is 10.96 ppb when the average time is 200 s. Benefiting from the all-optimization of photoacoustic excitation and detection, the MCEPA has near-field high-sensitivity gas detection capability immune to electromagnetic interference.
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Zhang H, Wang Z, Wang Q, Borri S, Galli I, Sampaolo A, Patimisco P, Spagnolo VL, De Natale P, Ren W. Parts-per-billion-level detection of hydrogen sulfide based on doubly resonant photoacoustic spectroscopy with line-locking. PHOTOACOUSTICS 2023; 29:100436. [PMID: 36570473 PMCID: PMC9768371 DOI: 10.1016/j.pacs.2022.100436] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/22/2022] [Accepted: 12/08/2022] [Indexed: 05/25/2023]
Abstract
We report on the development of a highly sensitive hydrogen sulfide (H2S) gas sensor exploiting the doubly resonant photoacoustic spectroscopy technique and using a near-infrared laser emitting at 1578.128 nm. By targeting the R(4) transition of H2S, we achieved a minimum detection limit of 10 part per billion in concentration and a normalized noise equivalent absorption coefficient of 8.9 × 10-12 W cm-1 Hz-1/2. A laser-cavity-molecule locking strategy is proposed to enhance the sensor stability for fast measurement when dealing with external disturbances. A comparison among the state-of-the-art H2S sensors using various spectroscopic techniques confirmed the record sensitivity achieved in this work.
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Affiliation(s)
- Hui Zhang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Wang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China
- CNR-INO – Istituto Nazionale di Ottica, and LENS – European Laboratory for Nonlinear Spectroscopy, 50019 Sesto Fiorentino, Italy
| | - Qiang Wang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Simone Borri
- CNR-INO – Istituto Nazionale di Ottica, and LENS – European Laboratory for Nonlinear Spectroscopy, 50019 Sesto Fiorentino, Italy
| | - Iacopo Galli
- CNR-INO – Istituto Nazionale di Ottica, and LENS – European Laboratory for Nonlinear Spectroscopy, 50019 Sesto Fiorentino, Italy
| | - Angelo Sampaolo
- PolySense Lab – Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Pietro Patimisco
- PolySense Lab – Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Vincenzo Luigi Spagnolo
- PolySense Lab – Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Paolo De Natale
- CNR-INO – Istituto Nazionale di Ottica, and LENS – European Laboratory for Nonlinear Spectroscopy, 50019 Sesto Fiorentino, Italy
| | - Wei Ren
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China
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Liu Q, Sun Y, Qiu X, Guo G, Li L, Gong T, Li C. Resonant photoacoustic spectrometer enhanced by multipass absorption for detecting atmospheric CH4 at the ppb-level. Front Chem 2022; 10:1021145. [PMID: 36212055 PMCID: PMC9532541 DOI: 10.3389/fchem.2022.1021145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 09/05/2022] [Indexed: 11/28/2022] Open
Abstract
A resonant photoacoustic spectrometer (PAS) was developed for detecting trace atmospheric CH4. The sensitivity of the PAS was significantly increased via a Herriott-type multipass cell with a beam pattern concentrated in the cavity. The effective optical pathlength of the PAS can be optimized to 6.8 m with 34 reflections and a diameter of 6 mm. A distributed feedback diode laser at 1,653 nm was employed as the light source, and wavelength modulation spectroscopy was used for the 2nd harmonic signal to reduce the noise of the system. The resonant cell of PA and optimal modulation frequency were obtained by varying the measurements. In comparison with a single path, the sensitivity of the multipass strategy was improved 13 times. To evaluate the long-term stability and minimum detection limit (MDL) of the system, an Allan variance analysis was performed, and the analysis illustrated that the MDL accomplished 116 ppb at an average time of 84 s. The system was utilized for 2 days test campaign to validate the feasibility and robustness of the sensor. The system provides a promising technique for online monitoring of greenhouse gasses.
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Affiliation(s)
- Qiang Liu
- Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, China
| | - Yi Sun
- Shanxi Engineering Research Center of Precision Measurement and Online Detection Equipment and School of Applied Science, Taiyuan University of Science and Technology, Taiyuan, China
| | - Xuanbing Qiu
- Shanxi Engineering Research Center of Precision Measurement and Online Detection Equipment and School of Applied Science, Taiyuan University of Science and Technology, Taiyuan, China
| | - Guqing Guo
- Shanxi Engineering Research Center of Precision Measurement and Online Detection Equipment and School of Applied Science, Taiyuan University of Science and Technology, Taiyuan, China
| | - Lin Li
- Shanxi Engineering Research Center of Precision Measurement and Online Detection Equipment and School of Applied Science, Taiyuan University of Science and Technology, Taiyuan, China
| | - Ting Gong
- Shanxi Engineering Research Center of Precision Measurement and Online Detection Equipment and School of Applied Science, Taiyuan University of Science and Technology, Taiyuan, China
| | - Chuanliang Li
- Shanxi Engineering Research Center of Precision Measurement and Online Detection Equipment and School of Applied Science, Taiyuan University of Science and Technology, Taiyuan, China
- *Correspondence: Chuanliang Li,
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Sampaolo A, Patimisco P, Giglio M, Zifarelli A, Wu H, Dong L, Spagnolo V. Quartz-enhanced photoacoustic spectroscopy for multi-gas detection: A review. Anal Chim Acta 2022; 1202:338894. [PMID: 35341511 DOI: 10.1016/j.aca.2021.338894] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/02/2021] [Accepted: 07/26/2021] [Indexed: 11/29/2022]
Abstract
Multi-gas detection represents a suitable solution in many applications, such as environmental and atmospheric monitoring, chemical reaction and industrial process control, safety and security, oil&gas and biomedicine. Among optical techniques, Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) has been demonstrated to be a leading-edge technology for addressing multi-gas detection, thanks to the modularity, ruggedness, portability and real time operation of the QEPAS sensors. The detection module consists in a spectrophone, mounted in a vacuum-tight cell and detecting sound waves generated via photoacoustic excitation within the gas sample. As a result, the sound detection is wavelength-independent and the volume of the absorption cell is basically determined by the spectrophone dimensions, typically in the order of few cubic centimeters. In this review paper, the implementation of the QEPAS technique for multi-gas detection will be discussed for three main areas of applications: i) multi-gas trace sensing by exploiting non-interfering absorption features; ii) multi-gas detection dealing with overlapping absorption bands; iii) multi-gas detection in fluctuating backgrounds. The fundamental role of the analysis and statistical tools will be also discussed in detail in relation with the specific applications. This overview on QEPAS technique, highlighting merits and drawbacks, aims at providing ready-to-use guidelines for multi-gas detection in a wide range of applications and operating conditions.
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Affiliation(s)
- Angelo Sampaolo
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy & Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China; Polysense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, Bari, 70126, Italy
| | - Pietro Patimisco
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy & Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China; Polysense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, Bari, 70126, Italy
| | - Marilena Giglio
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy & Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China; Polysense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, Bari, 70126, Italy
| | - Andrea Zifarelli
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy & Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China; Polysense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, Bari, 70126, Italy
| | - Hongpeng Wu
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy & Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China
| | - Lei Dong
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy & Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China.
| | - Vincenzo Spagnolo
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy & Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China; Polysense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, Bari, 70126, Italy.
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Lou C, Liu X, Wang Y, Zhang Y, Li Y, Yao J, Chang C, Ma Y, Liu X. Ultra-broadband optical detection from the visible to the terahertz range using a miniature quartz tuning fork. OPTICS LETTERS 2022; 47:1875-1878. [PMID: 35363758 DOI: 10.1364/ol.452984] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
We report and experimentally demonstrate a novel, to the best of our knowledge, sensitive and wideband optical detection strategy based on the light-induced thermoelastic effect in a miniature quartz tuning fork (mQTF) with low stiffness prongs. Compared with a traditional QTF, the soft prongs of the mQTF result in improved sensitivity. Experimental results demonstrate that the mQTF exhibits ∼54-fold superior sensitivity compared to a QTF, and the mQTF sensor has an ultra-broadband optical response, ranging from visible light to terahertz wavelengths. Its response time reaches 11.7 ms, and the minimum noise equivalent power (NEP) is measured to be 2.2 × 10-9 W Hz-1/2 at room temperature. The mQTF exhibits advantages in its cost-effectiveness, sensitivity, and ultra-broadband response, and provides a promising approach for the detection of low-dose optical and terahertz-wave radiation.
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Lang Z, Qiao S, Ma Y. Acoustic microresonator based in-plane quartz-enhanced photoacoustic spectroscopy sensor with a line interaction mode. OPTICS LETTERS 2022; 47:1295-1298. [PMID: 35290297 DOI: 10.1364/ol.452085] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/05/2022] [Indexed: 06/14/2023]
Abstract
An acoustic microresonator (AmR) based in-plane quartz-enhanced photoacoustic spectroscopy (IP-QEPAS) sensor with a line interaction mode is proposed for what is believed to be the first time. The interaction area for the acoustic wave of the proposed AmR, with a slotted sidewall, is not limited to a point of the quartz tuning fork (QTF) prongs, but extends along the whole plane of the QTF prongs. Sixteen types of AmRs are designed to identify the best parameters. Water vapor (H2O) is chosen as the analyte to verify the reported method. The results indicate that this AmR for IP-QEPAS with a line interaction mode not only provides a high signal level, but also reduces the thermal noise caused by the laser directly illuminating the QTF. Compared with standard IP-QEPAS without an AmR, the minimum detection limit (MDL) is improved by 4.11 times with the use of the technique proposed in this study.
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Ma Y, Hong Y, Qiao S, Lang Z, Liu X. H-shaped acoustic micro-resonator-based quartz-enhanced photoacoustic spectroscopy. OPTICS LETTERS 2022; 47:601-604. [PMID: 35103686 DOI: 10.1364/ol.449822] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
An H-shaped acoustic micro-resonator (AmR)-based quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor is demonstrated for the first time. The H-shaped AmR has the advantages of easy optical alignment, high utilization of laser energy, and reduction in optical noise. The parameter of the H-shaped AmR is designed based on the standing wave enhancement characteristic. The performance of the H-shaped AmR-based QEPAS sensor system and bare quartz tuning fork (QTF)-based sensor system are measured under the same conditions by choosing water vapor (H2O) as the target gas. Compared with the QEAPS sensor based on a bare QTF, the detection sensitivity of the optimal H-shaped AmR-based QEPAS sensor exhibits a 17.2 times enhancement.
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Liu X, Qiao S, Ma Y. Highly sensitive methane detection based on light-induced thermoelastic spectroscopy with a 2.33 µm diode laser and adaptive Savitzky-Golay filtering. OPTICS EXPRESS 2022; 30:1304-1313. [PMID: 35209293 DOI: 10.1364/oe.446294] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
In this manuscript, a highly sensitive methane (CH4) sensor based on light-induced thermoelastic spectroscopy (LITES) using a 2.33 µm diode laser with high power is demonstrated for the first time. A quartz tuning fork (QTF) with an intrinsic resonance frequency of 32.768 kHz was used to detect the light-induced thermoelastic signal. A Herriot multi-pass cell with an effective optical path of 10 m was adopted to increase the laser absorption. The laser wavelength modulation depth and concentration response of this CH4-LITES sensor were investigated. The sensor showed excellent long term stability when Allan deviation analysis was performed. An adaptive Savitzky-Golay (S-G) filtering algorithm with χ2 statistical criterion was firstly introduced to the LITES technique. The SNR of this CH4-LITES sensor was improved by a factor of 2.35 and the minimum detection limit (MDL) with an integration time of 0.1 s was optimized to 0.5 ppm. This reported CH4-LITES sensor with sub ppm-level detection ability is of great value in applications such as environmental monitoring and industrial safety.
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Li Z, Si G, Ning Z, Liu J, Fang Y, Si B, Cheng Z, Yang C. Highly Sensitive Sphere-Tube Coupled Photoacoustic Cell Suitable for Detection of a Variety of Trace Gases: NO 2 as an Example. SENSORS 2021; 22:s22010281. [PMID: 35009823 PMCID: PMC8749625 DOI: 10.3390/s22010281] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/26/2021] [Accepted: 12/28/2021] [Indexed: 11/16/2022]
Abstract
The concentration of trace gases in the atmospheric environment is extremely low, but it has a great impact on the living environment of organisms. Photoacoustic spectroscopy has attracted extensive attention in the field of trace gas detection because of its high sensitivity, good selectivity, and fast response. As the core of a photoacoustic detection setup, the photoacoustic cell has a significant impact on detection performance. To improve detection sensitivity, a sphere-tube coupled photoacoustic cell (STPAC) was developed, which was mainly composed of a diffuse-reflective sphere and an acoustic resonance tube. Modulated light was reflected multiple times in the sphere to increase optical path, and photoacoustic (PA) signals were further amplified by the tube. Based on STPAC, a PA gas detection setup was built with a laser diode (LD) at 450 nm as the light source. The experimental results showed that the minimum detection limit (noise equivalent concentration, NEC) of NO2 was ~0.7 parts per billion (ppb). Compared with the T-type PA cell (TPAC) in which the modulated light passed through the sphere, the signal-to-noise ratio of STPAC was increased by an order of magnitude at the same concentration of the NO2 sample.
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Affiliation(s)
- Zhengang Li
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
- University of Science and Technology of China, Hefei 230026, China
| | - Ganshang Si
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
- University of Science and Technology of China, Hefei 230026, China
| | - Zhiqiang Ning
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
- University of Science and Technology of China, Hefei 230026, China
| | - Jiaxiang Liu
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
| | - Yonghua Fang
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
- University of Science and Technology of China, Hefei 230026, China
- Correspondence:
| | - Beibei Si
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
- University of Science and Technology of China, Hefei 230026, China
| | - Zhen Cheng
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
- University of Science and Technology of China, Hefei 230026, China
| | - Changping Yang
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; (Z.L.); (G.S.); (Z.N.); (J.L.); (B.S.); (Z.C.); (C.Y.)
- University of Science and Technology of China, Hefei 230026, China
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Cao Y, Wang R, Peng J, Liu K, Chen W, Wang G, Gao X. Humidity enhanced N 2O photoacoustic sensor with a 4.53 μm quantum cascade laser and Kalman filter. PHOTOACOUSTICS 2021; 24:100303. [PMID: 34540587 PMCID: PMC8441064 DOI: 10.1016/j.pacs.2021.100303] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 05/09/2023]
Abstract
A high-sensitivity N2O photoacoustic sensor using a 4.53 μm quantum cascade laser was developed. Sharply enhancement of photoacoustic signal of N2O with the increasing of humidity was investigated experimentally. Finally, 2.3 % water vapor was added to the analyzed sample to improve the vibrational-translational (V-T) relaxation rate of N2O molecule transition, and therefore enhance the N2O photoacoustic signal. High performance with a minimum detection limit of 28 ppbv in 1 s and a measurement precision of 34 ppbv have been achieved, respectively. Kalman adaptive filtering was used to remove the shot-to-shot variability related to the real-time noise in the measurement data and further improve the measurement precision. Without sacrificing the time resolution of the system, the Kalman adaptive filtering improves the measurement precision of the system by 2.3 times. The ability of the N2O photoacoustic sensor was demonstrated by continuous measurement of atmospheric N2O concentration for a period of 7 h.
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Affiliation(s)
- Yuan Cao
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
| | - Ruifeng Wang
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
- University of Science and Technology of China, Hefei, 230026, China
| | - Jie Peng
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
- University of Science and Technology of China, Hefei, 230026, China
| | - Kun Liu
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
- Corresponding author.
| | - Weidong Chen
- Laboratoire de Physicochimie de l’Atmosphère, Université du Littoral Côte d’Opale, 189A, Av. Maurice Schumann, Dunkerque, 59140, France
| | - Guishi Wang
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
| | - Xiaoming Gao
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
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Luo J, Mou F, Sun Y, Li S. Retrieval of weak non-resonant photoacoustic signal with the chaotic oscillator algorithm. OPTICS EXPRESS 2021; 29:26509-26525. [PMID: 34615085 DOI: 10.1364/oe.431548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Photoacoustic (PA) spectroscopic technique has become a popular tool for trace gas detection and is especially suitable for in situ measurement of sulfur hexafluoride (SF6) decomposition components in gas insulated switchgear (GIS). However, the concentrations of SF6 decomposition components are generally very low and the resulting PA signals are too weak to be accurately retrieved with traditional methods. In this study, we proposed a Lyapunov exponent based chaotic oscillator algorithm to retrieve the weak PA signals of SF6 decomposition components. Retrieval of weak PA signals from strong noise background was achieved for both simulation and measurement perspectives. The results were compared with those based on phase-locked amplification technique. Both simulation and measurement results concluded that the proposed chaotic oscillator algorithm is superior to the phase-locked amplification in terms of accuracy, sensitivity and stability. Since most trace gases have weak absorption signatures in the atmosphere (below 1%), this study can provide valuable insights in dealt with such weak signals in remote sensing of atmosphere.
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15
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Qiao S, Ma Y, He Y, Patimisco P, Sampaolo A, Spagnolo V. Ppt level carbon monoxide detection based on light-induced thermoelastic spectroscopy exploring custom quartz tuning forks and a mid-infrared QCL. OPTICS EXPRESS 2021; 29:25100-25108. [PMID: 34614848 DOI: 10.1364/oe.434128] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
In this paper, we report on an ultra-highly sensitive light-induced thermoelastic spectroscopy (LITES)-based carbon monoxide (CO) sensor exploiting custom quartz tuning forks (QTFs) as a photodetector, a multi-pass cell and a mid-infrared quantum cascade laser (QCL) for the first time. The QCL emitting at 4.58 µm with output power of 145 mW was employed as exciting source and the multi-pass cell was employed to increase the gas absorption pathlength. To reduce the noise level, wavelength modulation spectroscopy (WMS) and second harmonic demodulation techniques were exploited. Three QTFs including two custom QTFs (#1 and #2) with different geometries and a commercial standard QTF (#3) were tested as photodetector in the gas sensor. When the integration time of the system was set at 200 ms, minimum detection limits (MDLs) of 750 part-per-trillion (ppt), 4.6 part-per-billion (ppb) and 5.8 ppb were achieved employing QTF #1 #2, and #3, respectively. A full sensor calibration was achieved using the most sensitive QTF#1, demonstrating an excellent linear response with CO concentration.
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16
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Zheng K, Zheng C, Hu L, Guan G, Ma Y, Song F, Zhang Y, Wang Y, Tittel FK. Light-induced off-axis cavity-enhanced thermoelastic spectroscopy in the near-infrared for trace gas sensing. OPTICS EXPRESS 2021; 29:23213-23224. [PMID: 34614589 DOI: 10.1364/oe.430745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/23/2021] [Indexed: 06/13/2023]
Abstract
A trace gas sensing technique of light-induced off-axis cavity-enhanced thermoelastic spectroscopy (OA-CETES) in the near-infrared was demonstrated by combing a high-finesse off-axis integrated cavity and a high Q-factor resonant quartz tuning fork (QTF). Sensor parameters of the cavity and QTF were optimized numerically and experimentally. As a proof-of-principle, we employed the OA-CETES for water vapor (H2O) detection using a QTF (Q-factor ∼12000 in atmospheric pressure) and a 10cm-long Fabry-Perot cavity (finesse ∼ 482). By probing a H2O line at 7306.75 cm-1, the developed OA-CETES sensor achieved a minimum detection limit (MDL) of 8.7 parts per million (ppm) for a 300 ms integration time and a normalized noise equivalent absorption (NNEA) coefficient of 4.12 × 10-9cm-1 WHz-1/2. Continuous monitoring of indoor and outdoor atmospheric H2O concentration levels was performed for verifying the sensing applicability. The realization of the proposed OA-CETES technique with compact QTF and long effective path cavity allows a class of optical sensors with low cost, high sensitivity and potential for long-distance and multi-point sensing.
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17
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Mi Y, Ma Y. Ultra-Highly Sensitive Ammonia Detection Based on Light-Induced Thermoelastic Spectroscopy. SENSORS 2021; 21:s21134548. [PMID: 34283097 PMCID: PMC8272073 DOI: 10.3390/s21134548] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 02/05/2023]
Abstract
This invited paper demonstrated an ultra-highly sensitive ammonia (NH3) sensor based on the light-induced thermoelastic spectroscopy (LITES) technique for the first time. A quartz tuning fork (QTF) with a resonance frequency of 32.768 kHz was employed as a detector. A fiber-coupled, continuous wave (CW), distributed feedback (DFB) diode laser emitting at 1530.33 nm was chosen as the excitation source. Wavelength modulation spectroscopy (WMS) and second-harmonic (2f) detection techniques were applied to reduce the background noise. In a one scan period, a 2f signal of the two absorption lines located at 6534.6 cm−1 and 6533.4 cm−1 were acquired simultaneously. The 2f signal amplitude at the two absorption lines was proved to be proportional to the concentration, respectively, by changing the concentration of NH3 in the analyte. The calculated R-square values of the linear fit are equal to ~0.99. The wavelength modulation depth was optimized to be 13.38 mA, and a minimum detection limit (MDL) of ~5.85 ppm was achieved for the reported NH3 sensor.
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Affiliation(s)
| | - Yufei Ma
- Correspondence: ; Tel.: +86-451-8641-3161
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Lou C, Chen H, Li X, Yang X, Zhang Y, Yao J, Ma Y, Chang C, Liu X. Graphene oxide and polydimethylsiloxane coated quartz tuning fork for improved sensitive near- and mid-infrared detection. OPTICS EXPRESS 2021; 29:20190-20204. [PMID: 34266113 DOI: 10.1364/oe.428003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
Sensitive and broadband infrared sensors are required for security and medical applications, as few can rapidly and sensitively detect infrared without uncooled devices. Here, we report a wideband optical-detection strategy based on the thermoelastic effect of a coating-enhanced quartz tuning fork (QTF) and study the feasibility of using an atomic force probe operating in contact mode to monitor the vibration. Graphene oxide (GO) and polydimethylsiloxane (PDMS) coating were applied on the QTF's surface to improve the light absorption and the thermal-mechanical conversion efficiency. Experimental results showed that the bi-layer coatings yielded a maximum gain factor of 8 in response amplitude and signal-to-noise ratio (SNR) than that of a bare QTF, respectively. Lasers with wavelengths of 1512 nm and 10.6 µm were used as the typical representative light source to test the photoresponse of the QTF detector. The device displays a broadband photoresponse covering the near-infrared to mid-infrared range at room temperature, high performance with the maximum photoresponsivity of 85.76 V·mW-1, and 1σ detection limit of 0.056 µW; the lowest noise equivalent power (NEP) of 1.35 nW·Hz-1/2 and 43.9 ms response speed is also achieved. The preparation process of detector is simple and easy to implement; the resulting device exhibits high responsivity and wide wavelength response ranging at least from 1512 to 10600 nm, compared with custom QTF; and the surface coating strategy potentially enables the construction of a new class of low-cost photodetection sensors operated at room temperature.
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Lang Z, Qiao S, He Y, Ma Y. Quartz tuning fork-based demodulation of an acoustic signal induced by photo-thermo-elastic energy conversion. PHOTOACOUSTICS 2021; 22:100272. [PMID: 34040982 PMCID: PMC8144470 DOI: 10.1016/j.pacs.2021.100272] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/22/2021] [Accepted: 05/10/2021] [Indexed: 05/06/2023]
Abstract
A gas sensing method based on quartz-enhanced photothermal spectroscopy (QEPTS) demodulated by quartz tuning fork (QTF) sensing acoustic wave is reported for the first time. Different from traditional QEPTS, the method proposed in this paper utilizes the second QTF to sense acoustic wave produced by the first QTF owing to the vibration resulted from photo-thermo-elastic effect. This indirect demodulation by acoustic wave sensing can avoid QTF being irradiated by laser beam and therefore get less noise and realize better detection sensitivity. Four different sensing configurations are designed and verified. Acetylene (C2H2) with a volume concentration of 1.95 % is selected as the target gas. A model of sound field produced by the first QTF vibrating is established by finite element method to explain the variation trend of signal and noise in the second QTF. The measured results indicate that this technique had an enhanced signal-to-noise ratio (SNR) of 1.36 times when compared to the traditional QEPTS. Further improvement methods for such technique is proposed.
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Trace CH4 Gas Detection Based on an Integrated Spherical Photoacoustic Cell. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11114997] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This paper presents an integrated spherical photoacoustic cell (SPAC) for trace methane (CH4) gas detection. Theoretical analysis and analogue simulations are carried out to analyze the acoustic field distribution of the SPAC at resonant and non-resonant modes. The finite element simulation results based on COMSOL show that the first-order radial resonant frequency and second-order angular resonant frequency are 24,540 Hz and 18,250 Hz, respectively, which show good agreements with the formula analysis results. The integrated SPAC, together with a high-speed spectrometer and a distributed feedback (DFB) laser source, makes up a photoacoustic (PA) spectroscopy (PAS) system, which is employed for CH4 detection. The minimum detection limit (MDL) is measured to be 126.9 parts per billion (ppb) at an average time of 1000 s. The proposed SPAC has an integrated, miniaturized and all-optical structure, which can be used for remote and long-distance trace gas detection.
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21
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Ma Y, Lang Z, He Y, Qiao S, Li Y. Ultra-Highly Sensitive Hydrogen Chloride Detection Based on Quartz-Enhanced Photothermal Spectroscopy. SENSORS (BASEL, SWITZERLAND) 2021; 21:3563. [PMID: 34065442 PMCID: PMC8160860 DOI: 10.3390/s21103563] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 12/24/2022]
Abstract
Combining the merits of non-contact measurement and high sensitivity, the quartz-enhanced photothermal spectroscopy (QEPTS) technique is suitable for measuring acid gases such as hydrogen chloride (HCl). In this invited paper, we report, for the first time, on an ultra-highly sensitive HCl sensor based on the QEPTS technique. A continuous wave, distributed feedback (CW-DFB) fiber-coupled diode laser with emission wavelength of 1.74 µm was used as the excitation source. A certified mixture of 500 ppm HCl:N2 was adapted as the analyte. Wavelength modulation spectroscopy was used to simplify the data processing. The wavelength modulation depth was optimized. The relationships between the second harmonic (2f) amplitude of HCl-QEPTS signal and the laser power as well as HCl concentration were investigated. An Allan variance analysis was performed to prove that this sensor had good stability and high sensitivity. The proposed HCl-QEPTS sensor can achieve a minimum detection limit (MDL) of ~17 parts per billion (ppb) with an integration time of 130 s. Further improvement of such an HCl-QEPTS sensor performance was proposed.
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Affiliation(s)
- Yufei Ma
- National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150001, China; (Z.L.); (Y.H.); (S.Q.); (Y.L.)
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Qiao S, He Y, Ma Y. Trace gas sensing based on single-quartz-enhanced photoacoustic-photothermal dual spectroscopy. OPTICS LETTERS 2021; 46:2449-2452. [PMID: 33988607 DOI: 10.1364/ol.423801] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A single-quartz-enhanced dual spectroscopy (S-QEDS)-based trace gas sensor is reported for the first time, to the best of our knowledge. In S-QEDS, a quartz tuning fork (QTF) was utilized to detect the photoacoustic and photothermal signals simultaneously and added the two signals together. The S-QEDS technique not only improved the detection performance but also avoided the issue of resonant frequency mismatching of QTFs for the multi-QTFs-based sensor systems. Water vapor (${\rm H}_2{\rm O}$) was selected as the target gas to investigate the S-QEDS sensor performance. The photoacoustic, photothermal, and composited signals were measured, respectively, under the same conditions. The experimental results verified the ideal adding of the photoacoustic and photothermal signals by using a single QTF in this S-QEDS sensor system.
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Gong Z, Wu G, Jiang X, Li H, Gao T, Guo M, Ma F, Chen K, Mei L, Peng W, Yu Q. All-optical high-sensitivity resonant photoacoustic sensor for remote CH 4 gas detection. OPTICS EXPRESS 2021; 29:13600-13609. [PMID: 33985092 DOI: 10.1364/oe.424387] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This paper presents an all-optical high-sensitivity resonant photoacoustic (PA) sensor to realize remote, long-distance and space-limited trace gas detection. The sensor is an integration of a T-type resonant PA cell and a particular cantilever-based fiber-optic acoustic sensor. The finite element simulations about the cantilever vibration mode and the PA field distributions are carried out based on COMSOL. The all-optical high-sensitivity resonant PA sensor, together with a high-speed spectrometer and a DFB laser source, makes up of a photoacoustic spectroscopy (PAS) system which is employed for CH4 detection. The measured sensitivity is 0.6 pm/ppm in the case of 1000 s average time, and the minimum detection limit (MDL) reaches 15.9 parts per billion (ppb). The detective light source and the excitation light source are all transmitted by optical fibers, therefore remote and long-distance measurement of trace gas can be realized. Furthermore, the excitation light source and the acoustic sensor are designed at the same side of the PA cell, the sensor may be used for space-limited trace gas detection.
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Lou C, Li X, Chen H, Yang X, Zhang Y, Yao J, Liu X. Polymer-coated quartz tuning fork for enhancing the sensitivity of laser-induced thermoelastic spectroscopy. OPTICS EXPRESS 2021; 29:12195-12205. [PMID: 33984984 DOI: 10.1364/oe.421356] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
A novel laser-induced thermoelastic spectroscopy (LITES) sensor based on a polymer-coated quartz tuning fork (QTF) is reported. Two types of polymer films with different thicknesses are deposited on commercially available QTF to improve the conversion efficiency of laser energy deposition into vibration. CO2 was selected as the target analyte for validation measurements. The experimental results indicate that by introducing a polymer coating, a maximum gain factor of 3.46 and 3.21 is attained for the signal amplitude and signal-to-noise ratio (SNR), respectively, when compared to traditional LITES that using only a bare QTF. A minimum detectable concentration of 0.181% can be obtained, corresponding to a normalized noise equivalent absorption coefficient (NNEA) of 1.74×10-11 cm-1·W·Hz-1/2, and the measurement precision is approximately 0.06% with an averaging time of 200 s. Here, we show what we believe is the first demonstration of polymer coated QTF for LITES sensing, compared with custom QTF, the design has the virtues of lower cost, simple and easy-to-operate, is a promising new strategy for sensitive trace gas analysis.
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