{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:51:24Z","timestamp":1760241084576,"version":"build-2065373602"},"reference-count":41,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2019,11,28]],"date-time":"2019-11-28T00:00:00Z","timestamp":1574899200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key R&amp;D Program of China","award":["2016YFB0401903"],"award-info":[{"award-number":["2016YFB0401903"]}]},{"name":"Open Research fund of Key Laboratory of Atmospheric Optics, Chinese Academy of Sciences","award":["JJ-2018-02"],"award-info":[{"award-number":["JJ-2018-02"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61675122, 61875107, 61905134 and 11704236"],"award-info":[{"award-number":["61675122, 61875107, 61905134 and 11704236"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Research Project Supported by Shanxi Scholarship Council of China","award":["2017-016"],"award-info":[{"award-number":["2017-016"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Due to their advantages of having a wide bandwidth, low cost, and being easy to obtain, traditional photodetectors (PDs) are being widely applied in measurements of transient signals. The spatial inhomogeneity of such PD temporal responses was measured directly to account for the PD spatial effect of decay rate due to poor alignment in continuous wave cavity ringdown spectroscopy (CW-CRDS) experiments. Based on the measurements of three PDs (i.e., model 1611 (Newport), model 1811 (Newport), and model PDA10CF-EC (Thorlabs)), all the temporal responses followed a tendency of declining first and then rising, and steady platforms existed for the last two PDs. Moreover, as we expected, the closer the PD center was, the faster the response. On the other hand, the initial shut-off amplitude generally reached a larger value for a faster temporal response. As a result, the spatial effect can strongly influence the spectral line shape and value, which will introduce more errors into the precise measurements of spectral parameters using the CRDS technique if this effect is not considered. The defined effective detection area (EDA) of the PDs, which was close to the active area given by manufacturers, was the key parameter that should be paid more attention by researchers. Therefore, the PD should be aligned perfectly to make sure that the EDA covers the laser spot completely.<\/jats:p>","DOI":"10.3390\/s19235232","type":"journal-article","created":{"date-parts":[[2019,11,28]],"date-time":"2019-11-28T10:54:10Z","timestamp":1574938450000},"page":"5232","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Influence of Spatial Inhomogeneity of Detector Temporal Responses on the Spectral Fidelity in Continuous Wave Cavity Ringdown Spectroscopy"],"prefix":"10.3390","volume":"19","author":[{"given":"Zhensong","family":"Cao","sequence":"first","affiliation":[{"name":"Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China"}]},{"given":"Zhixin","family":"Li","sequence":"additional","affiliation":[{"name":"School of Software, Shanxi University, Taiyuan 030006, China"}]},{"given":"Fei","family":"Xu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China"},{"name":"Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China"}]},{"given":"Yongqian","family":"Wu","sequence":"additional","affiliation":[{"name":"Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China"}]},{"given":"Zixin","family":"Zhou","sequence":"additional","affiliation":[{"name":"Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2685-5595","authenticated-orcid":false,"given":"Zhaomin","family":"Tong","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China"},{"name":"Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China"}]},{"given":"Weiguang","family":"Ma","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China"},{"name":"Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China"}]},{"given":"Wenyue","family":"Zhu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1007\/s00340-010-4132-5","article-title":"Analysis of trace impurities in semiconductor gas via cavity-enhanced direct frequency comb spectroscopy","volume":"100","author":"Cossel","year":"2010","journal-title":"Appl. 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