Integrated multi-mode glass ceramic fiber for high-resolution temperature sensing

Optical temperature sensors, which can accurately detect temperature in biological systems, are crucial to the development of healthcare monitoring. To challenge the state-of-art technology, it is necessary to design single luminescence center doped materials with multi-wavelength emission for optical temperature sensors with more modes and higher resolution. Here, an Er3+ single-doped KYF4 nanocrystals glass ceramic with an obvious thermochromic phenomenon is reported for the first time, which shows a different temperature-dependent green, red, and near-infrared luminescence behavior based on thermal disturbance model. In addition, Er3+ single-doped GC fiber was drawn and fabricated into multi-mode optical fiber temperature sensor, which has superior measured temperature resolution (＜0.5 ​°C), excellent detection limit (0.077 ​°C), and high correlation coefficient (R2) of 0.99997. More importantly, this sensor can monitor temperature in different scenarios with great environmental interference resistance and repeatability. These results indicate that our sensor shows great promise as a technology for environmental and healthcare monitoring, and it provides a route for the design of optical fiber temperature sensors with multi-mode and high resolution. The article shows an Er3+ single-doped KYF4 nanocrystals glass ceramic (GC) with an obvious thermochromic phenomenon. In addition, Er3+ single-doped GC fiber was drawn and fabricated into multi-mode optical fiber temperature sensor, which can monitor temperature in different scenarios with great environmental interference resistance and repeatability. [Display omitted] •For the first time, Er3+ single-doped GC exhibits different temperature-dependent emission intensities at 540, 664, and 798 ​nm, resulting in an obvious thermochromic phenomena from green to orange-yellow.•Er3+ single-doped GC fiber was drawn and fabricated into multi-mode optical fiber temperature sensor, which shows ultra-low measured temperature resolution (＜0.5 ​°C), excellent detection limit (0.077 ​°C), and high correlation coefficient (R2) of 0.99997.•The multi-mode temperature sensor can monitor temperature in different scenarios with great environmental interference resistance, high precision, and repeatability.