{"id":687,"date":"2026-02-04T18:53:04","date_gmt":"2026-02-04T18:53:04","guid":{"rendered":"https:\/\/wp.icmm.csic.es\/realm\/?p=687"},"modified":"2026-02-04T18:53:04","modified_gmt":"2026-02-04T18:53:04","slug":"overcoming-the-limitations-of-upconversion-thermometry-glass-ceramic-optical-fiber-thermometers","status":"publish","type":"post","link":"https:\/\/wp.icmm.csic.es\/realm\/2026\/02\/04\/overcoming-the-limitations-of-upconversion-thermometry-glass-ceramic-optical-fiber-thermometers\/","title":{"rendered":"Overcoming the limitations of upconversion thermometry: Glass-ceramic optical fiber thermometers"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-688\" src=\"https:\/\/wp.icmm.csic.es\/realm\/wp-content\/uploads\/sites\/28\/2026\/02\/GCs1-300x272.jpg\" alt=\"\" width=\"300\" height=\"272\" srcset=\"https:\/\/wp.icmm.csic.es\/realm\/wp-content\/uploads\/sites\/28\/2026\/02\/GCs1-300x272.jpg 300w, https:\/\/wp.icmm.csic.es\/realm\/wp-content\/uploads\/sites\/28\/2026\/02\/GCs1.jpg 597w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/>Oxyfluoride glass-ceramics (GCs) containing LaF<sub>3<\/sub> or \u03b1-NaLuF<sub>4<\/sub> nanocrystals, co-doped with 2 mol% Yb<sup>3+<\/sup> and 0.5 mol% Er<sup>3+<\/sup>, are considered as core materials for the implementation of optical fiber photoluminescence (PL) thermometers. A dual-channel ratiometric thermometry approach combining green (UC, <sup>2<\/sup>H<sub>11\/2<\/sub> \u2192 <sup>4<\/sup>I<sub>15\/2 <\/sub>vs <sup>4<\/sup>S<sub>3\/2 <\/sub>\u2192 <sup>4<\/sup>I<sub>15\/2<\/sub>) and infrared emissions (IR, <sup>4<\/sup>I<sub>13\/2<\/sub>(m\u00b4) \u2192 <sup>4<\/sup>I<sub>15\/2 <\/sub>vs <sup>4<\/sup>I<sub>13\/2<\/sub>(m) \u2192 <sup>4<\/sup>I<sub>15\/2<\/sub>) allows the extension of the sensing temperature range above the UC luminescence quenching (at \u2248 650 K) by over 100 K (LaF<sub>3<\/sub>) or 150 K (\u03b1-NaLuF<sub>4<\/sub>). The IR channel, working near \u03bb= 1.55 mm, operates at the wavelength of minimum propagation losses of optical fibers, facilitating long-distance propagation of luminescence signals. The UC channel in LaF<sub>3<\/sub>-GC shows a maximum absolute sensitivity S<sub>A<\/sub> = 102 \u00d7 10<sup>-4<\/sup> K<sup>-1<\/sup> at 602 K in glass and S<sub>A<\/sub> = 71 \u00d7 10<sup>-4<\/sup> K<sup>-1<\/sup> at 591 K in GC with thermal resolution \u03b4 = 1.5\u20133 K. The \u03b1-NaLuF<sub>4<\/sub>-glass and -GC reach UC S<sub>A<\/sub> = 90 \u00d7 10<sup>-4<\/sup> K<sup>-1<\/sup> at 698\u00a0K. The IR channel in both GCs, based on PL intensity ratios at 1498 nm and 1610 nm, exhibits S<sub>A<\/sub> \u2248 30-10 \u00d7 10<sup>-4<\/sup> K<sup>-1<\/sup> for the 300-800 K range.<\/p>\n<p>Published in Advanced Optical Materials vol 14, pg e01720, 2026<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Oxyfluoride glass-ceramics (GCs) containing LaF3 or \u03b1-NaLuF4 nanocrystals, co-doped with 2 mol% Yb3+ and 0.5 mol% Er3+, are considered as core materials for the implementation of optical fiber photoluminescence (PL) thermometers. A dual-channel ratiometric thermometry approach combining green (UC, 2H11\/2 \u2192 4I15\/2 vs 4S3\/2 \u2192 4I15\/2) and infrared emissions (IR, 4I13\/2(m\u00b4) \u2192 4I15\/2 vs 4I13\/2(m) &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/wp.icmm.csic.es\/realm\/2026\/02\/04\/overcoming-the-limitations-of-upconversion-thermometry-glass-ceramic-optical-fiber-thermometers\/\" class=\"more-link\">Continuar leyendo<span class=\"screen-reader-text\"> \u00abOvercoming the limitations of upconversion thermometry: Glass-ceramic optical fiber thermometers\u00bb<\/span><\/a><\/p>\n","protected":false},"author":51,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-687","post","type-post","status-publish","format-standard","hentry","category-sin-categoria"],"_links":{"self":[{"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/posts\/687","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/users\/51"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/comments?post=687"}],"version-history":[{"count":2,"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/posts\/687\/revisions"}],"predecessor-version":[{"id":691,"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/posts\/687\/revisions\/691"}],"wp:attachment":[{"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/media?parent=687"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/categories?post=687"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/realm\/wp-json\/wp\/v2\/tags?post=687"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}