[1] ENGELN R, BERDEN G, PEETERS R et al. Cavity enhanced absorption and cavity enhanced magnetic rotation spectroscopy[J]. Review of Scientific Instruments, 69, 3763-3769(1998).

[2] O'KEEFE A, DEACON D. Cavity ring-down optical spectrometer for absorption measurements using pulsed laser sources[J]. Review of Scientific Instruments, 59, 2544-2551(1988).

[3] O'KEEFE A. Integrated cavity output analysis of ultra-weak absorption[J]. Chemical Physics Letters, 293, 331-336(1998).

[4] O'KEEFE A, SCHERER J J, PAUL J B. Cw Integrated cavity output spectroscopy[J]. Chemical Physics Letters, 307, 343-349(1999).

[5] PAUL J B, LAPSON L, ANDERSON J G. Ultrasensitive absorption spectroscopy with a high-finesse optical cavity and off-axis alignment[J]. Applied Optics, 40, 4904-4910(2001).

[6] BAER D S, PAUL J B, GUPTA M, O΄KEEFE A. Sensitive absorption measurements in the nearinfrared region using off-axis integrated cavityoutput spectroscopy[J]. Applied Physics B, 75, 261-265(2002).

[7] WANG J J, TIAN X, DONG Y et al. Enhancing off-axis integrated cavity output spectroscopy (OA-ICOS) with radio frequency white noise for gas sensing.[J]. Optics Express, 27, 30517-30529(2019).

[8] MSHESH P, SREENIVAS G, RAO P V N et al. High-precision surface-level CO2 and CH4 using off-axis integrated cavity output spectroscopy (OA-ICOS) over Shadnagar, India[J]. International Journal of Remote Sensing, 36, 5754-5765(2015).

[9] LIU Zidi, ZHENG Kaiyuan, ZHANG Haipeng et al. Off-axis integrated cavity-enhanced infrared laser carbon dioxide sensor system[J]. Acta Photonica Sinica, 49, 1149014(2020).

[10] SILVA M L, SONNENFROH D M, ROSEN D I et al. Integrated cavity output spectroscopy measurements of NO levels in breath with a pulsed room-temperature QCL[J]. Applied Physics B, 81, 705-710(2005).

[11] AZHAR M, MANDON J, NEERINCX et al. A widely tunable, near-infrared laser-based trace gas sensor for hydrogen cyanide (HCN) detection in exhaled breath[J]. Applied Physics B, 123, 268(2017).

[12] WITINSKI M F, SAYRES D S, ANDERSON J G. High precision methane isotopologue ratio measurements at ambient mixing ratios using integrated cavity output spectroscopy[J]. Applied Physics B, 102, 375-380(2011).

[13] KASYUTICH V L, CANOSA-MAS C E, PFRANG C et al. Off-axis continuous-wave cavity-enhanced absorption spectroscopy of narrow-band and broadband absorbers using red diode lasers[J]. Applied Physics B, 75, 755-761(2002).

[14] ZYBIN A, KURITSYN Y A, MIRONENKO V R et al. Cavity enhanced wavelength modulation spectrometry for application in chemical analysis[J]. Applied Physics B, 78, 103-109(2004).

[15] BAKHIRKIN Y A, KOSTEREV A A, ROLLER C et al. Mid-infrared quantum cascade laser based off-axis integrated cavity output spectroscopy for biogenic nitric oxide detection[J]. Applied Optics, 43, 2257-2266(2004).

[16] BAKHIRKIN Y A, KOSTEREV A A, CURL R F et al. Sub-ppbv nitric oxide concentration measurements using cw thermoelectrically cooled quantum cascade laser-based integratedcavity output spectroscopy[J]. Applied Physics B, 82, 149-154(2006).

[17] ZHAO W X, GAO X M, CHEN W D et al. Wavelength modulated off-axis integrated cavity output spectroscopy in the near infrared[J]. Applied Physics B, 86, 353-359(2007).

[18] WU Tao, XU Dong, HE Xingdao et al. Off-axis integrated cavity output spectroscopy technique based on wavelength modulation[J]. Acta Optica Sinica, 37, 389-398(2017).

[19] MONKS P S. Gas-phase radical chemistry in the troposphere[J]. Chemical Society Reviews, 34, 376-395(2005).

[20] CARSLAW N, CARSLAW D. The gas-phase chemistry of urban atmosphere[J]. Surveys in Geophysics, 22, 31-53(2001).

[21] STON D, WHALLEY L K, HEARD D E. Tropospheric OH and HO2 radicals: field measurements and model comparisons[J]. Chemical Society Reviews, 41, 6348(2012).

[22] LELIEVELD J, BUTLER T M, CROWLEY J N et al. Atmospheric oxidation capacity sustained by a tropical forest[J]. Nature, 452, 737-740(2008).

[23] RICKLY P, STEVENS P S. Measurements of a potential interference with laser-induced fluorescence measurements of ambient OH from the ozonolysis of biogenic alkenes[J]. Atmospheric Measurement Techniques, 11, 1-16(2017).

[24] HAUSMANN M, BRANDENBURGER U, BRAUERS T et al. Simple Monte Carlo methods to estimate the spectra evaluation error in differential-optical-absorption spectroscopy[J]. Applied Optics, 38, 462-475(1999).

[25] YANG N N, FANG B, ZHAO W X et al. Optical-feedback cavity-enhanced absorption spectroscopy for OH radical detection at 2.8 μm using a DFB diode laser[J]. Optics Express, 30, 15238-15249(2022).

[26] MALARA P, MADDALONI P, GAGLIARDI G et al. Combining a difference-frequency source with an off-axis high-finesse cavity for trace-gas monitoring around 3 μm[J]. Optics Express, 14, 1304-1313(2006).

[27] FIEDLER S E, HESE A, RUTH A A. Incoherent broad-band cavity-enhanced absorption spectroscopy[J]. Chemical Physics Letters, 371, 284-294(2003).

[28] TAN Z Q, LONG X W, FENG X W et al. The study of wavelength modulation off-axis integrated cavity output spectroscopy in the case of Lorentzian absorption profile[J]. Optics Communications, 284, 852-856(2011).

[29] KLUCZYNSKI P, GUSTAFSSON J, LINDBERG A M et al. Wavelength modulation absorption spectrometry-an extensive scrutiny of the generation of signals[J]. Spectrochimica Acta, Part B. Atomic Spectroscopy, 56, 1277-1354(2001).

[30] DING Wuwen, SUN Liqun, YI Luying. High sensitive scheme for methane remote sensor based on tunable diode laser absorption spectroscopy[J]. Acta Physica Sinica, 66, 53-61(2017).

[31] CHEN Hao, JU Yu, HAN Li. Research on the relationship between modulation depth and center of high order harmonic in TDLAS wavelength modulation method[J]. Spectroscopy and Spectral Analysis, 41, 3676-3681(2021).

[32] GORDON I E, ROTHMAN L S, HARGREAVES R J et al. The HITRAN2020 molecular spectroscopic database[J]. Journal of Quantitative Spectroscopy and Radiative Transfer, 277, 107949(2022).

[33] NILLSON E J K, ESKEBJERG C, JOHNSON M S. A photochemical reactor for studies of atmospheric chemistry[J]. Atmospheric Environment, 43, 3029-3033(2009).

[34] GUO Guangcan. Some physical problems of amplified spontaneous emission[J]. Physics, 10, 593-596(1982).

[36] NADEZHDINSKII A I. Diode laser spectroscopy: precise spectral line shape measurements[J]. Spectrochimica Acta Part A, 52, 1041-1060(1996).

[37] WELDON V, MCINERNEY D, PHELAN R et al. Characteristics of several NIR tuneable diode lasers for spectroscopic based gas sensing: a comparison[J]. Spectrochim Acta A, 63, 1013-1020(2006).

[38] KASYUTICH V L, MARTIN P A, HOLDSWORTH R J. An off-axis cavity-enhanced absorption spectrometer at 1 605 nm for the 12CO2/13CO2 measurement[J]. Applied Physics B, 85, 413-420(2006).

[39] ROMANINI D, LEHMANN K K. Ring-down cavity absorption spectroscopy of the very weak HCN overtone bands with six, seven, and eight stretching quanta[J]. The Journal of Chemical Physics, 99, 6287-6301(1993).

[40] HELDEN J H, SCHRAM D C, ENGELN R. Phase-shift cavity ring-down spectroscopy to determine absolute line intensities[J]. Chemical Physics Letters, 400, 320-325(2004).

[41] KASYUTICH V L, MARTIN P A, HOLDSWORTH R J. Effect of broadband amplified spontaneous emission on absorption measurements in phase-shift off-axis cavity enhanced absorption spectroscopy[J]. Chemical Physics Letters, 430, 429-434(2006).

[42] KASYUTICH V L, MARTINP A. On quantitative measurements in phase-shift off-axis cavity-enhanced absorption spectroscopy[J]. Chemical Physics Letters, 446, 206-211(2007).

[43] ZHAO W X, GAO X M, DENG L H et al. Absorption spectroscopy of formaldehyde at 1.573 μm[J]. Journal of Quantitative Spectroscopy & Radiative Transfer, 107, 331-339(2007).

[44] GUAN Mengxue, CHEN Daqiang, HU Shiqi et al. Theoretical insights into ultrafast dynamics in quantum materials[J]. Ultrafast Science, 2022, 9767251(2022).

[45] ZHAO W X, FANG B, LINX X et al. Superconducting-magnet-based faraday rotation spectrometer for real time in situ measurement of OH radicals at 106 molecule/cm3 level in an atmospheric simulation chamber[J]. Analytical Chemistry, 90, 3958-3964(2018).