Abstract Optical thermometer based on the non-contact fluorescence intensity ratio technique of two thermally-couple levels has huge potential applications in many fields, such as the electric power industry and in-situ physiological measurements. In the paper, the Yb3+/Nd3+ codoped Bi4Ti3O12 nanocrystal ratio thermometer has prepared by solid-phase sintering. The two thermally-couple levels are Nd3+:4F7/2 (emission peak around 753 nm) and Nd3+:4F5/2 (emission peak at 805 nm), respectively. The optical thermometer has based on the upconversion in near-infrared luminescence under 980 nm excitation with low power of 1.87 W/cm2. Due to the relatively low pump power, the effect of the excitation heat effect on the material is reduced. This resulted in a relatively high relative sensitivity (SR = 1% K−1) in the temperature range of 323–573 K. In addition to the characteristics, the excellent repeatability (σ = 1.5%) of the fluorescence intensity ratio between the two Nd3+ emission peaks makes Yb3+/Nd3+ codoped Bi4Ti3O12 microcrystals a promising non-contact near-infrared ratio thermometer.

中文翻译：

---

基于Yb3+/Nd3+共掺杂Bi4Ti3O12微晶的非接触式荧光强度比光学温度计

摘要 基于非接触式两级热电偶荧光强度比技术的光学温度计在电力工业、原位生理测量等诸多领域具有巨大的应用潜力。本文采用固相烧结法制备了Yb3+/Nd3+共掺杂Bi4Ti3O12纳米晶比温度计。两个热偶能级分别是 Nd3+:4F7/2（发射峰值在 753 nm 附近）和 Nd3+:4F5/2（发射峰值在 805 nm）。光学温度计基于近红外发光在 980 nm 激发下的上转换，低功率为 1.87 W/cm2。由于相对较低的泵浦功率，减少了激发热效应对材料的影响。这导致在 323-573 K 的温度范围内具有相对较高的相对灵敏度 (SR = 1% K−1)。