{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T09:03:22Z","timestamp":1780477402402,"version":"3.54.1"},"reference-count":29,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,5,30]],"date-time":"2026-05-30T00:00:00Z","timestamp":1780099200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Natural Science Foundation of Hebei Province of China","award":["A2023202014"],"award-info":[{"award-number":["A2023202014"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>To meet the demand for highly sensitive temperature sensing in low-temperature environments, a surface plasmon resonance photonic crystal fiber (SPR-PCF) sensor with a central air hole and a dual-layer air-hole arrangement is designed and optimized. In this work, these air-hole features are used for mode-field regulation in a low-temperature sensing structure based on surface plasmon resonance (SPR), together with a polished gold film and an ethanol\/chloroform (1:1) temperature-sensitive medium. The finite element method (FEM) was employed to analyze the resonance behavior and thermal response, and key structural parameters, including gold-film thickness, air-hole sizes, and radial positions, were optimized through cumulative parametric scanning. The optimized sensor shows good temperature response from \u221225 \u00b0C to 40 \u00b0C, with a maximum sensitivity of 36 nm\/\u00b0C, a full width at half-maximum (FWHM) of 18.57 nm, and a figure of merit (FOM) of 1.2923. It is promising for cold-chain monitoring, low-temperature storage and transportation, and low-temperature sensing.<\/jats:p>","DOI":"10.3390\/mi17060679","type":"journal-article","created":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T07:58:38Z","timestamp":1780473518000},"page":"679","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Study and Optimization of a High-Performance SPR-PCF Temperature Sensor for Low-Temperature Monitoring Applications"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-4965-2152","authenticated-orcid":false,"given":"Xinyuan","family":"Wang","sequence":"first","affiliation":[{"name":"Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-3182-8432","authenticated-orcid":false,"given":"Ke","family":"Jia","sequence":"additional","affiliation":[{"name":"Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-1549-9103","authenticated-orcid":false,"given":"Zixi","family":"Fu","sequence":"additional","affiliation":[{"name":"Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yifan","family":"Feng","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingheng","family":"Xiao","sequence":"additional","affiliation":[{"name":"Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yulin","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenjiang","family":"Ye","sequence":"additional","affiliation":[{"name":"Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2059","DOI":"10.1103\/PhysRevLett.58.2059","article-title":"Inhibited spontaneous emission in solid-state physics and electronics","volume":"58","author":"Yablonovitch","year":"1987","journal-title":"Phys. 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