A Reliable Anti-Interference Probe Based on Fluorescence Intensity Ratio Technique for Cryogenic Temperature Detection

In this paper, a reliable anti-interference probe based on fluorescence intensity ratio technique is proposed for cryogenic temperature detection in refrigeration process, the sensing unit of which is based on a self-made coreless tellurite optical fiber (TOF) co-doped with Er3+/Yb3+ ions. The temperature information was demodulated by analyzing the fluorescence spectral changes. In order to meet the needs of practical applications, the dual-curing method was applied to realize the TOF splicing, and the thin-walled silica tube was used to provide robust packaging. For the first time, the anti-cross-sensitive properties of the fluorescent probe under vibration and liquid interference were quantified, and the repeated response deviation was on the order of 10(-5). The actual working capacity of the probe was experimentally investigated by applying it to measuring the circulating exhale and cryogenic equipment, in which a fast time response of about 2.11 s and a small absolute error of 0.80 K were obtained. The probe has good stability and repeatability, and can work stably even in complex environments with vibrations and liquids, showing strong anti-interference ability. In addition, the robust package and easy method make the probe suitable for mass fabrication.