利用稀土离子热耦合能级对的荧光强度比进行温度传感具有高精度、非接触的优势，然而荧光温度猝灭、热辐射干扰以及非玻尔兹曼分布参数等因素制约了其应用和发展。本项目提出以钆作为荧光激活离子、通过深紫外光激发布局6PJ能级，利用6PJ能级的荧光强度比进行测温。选择钆作为激活离子的优势在于：钆离子能级禁带宽度大，减少了无辐射弛豫，降低了荧光的温度猝灭；钆离子荧光处于背景热辐射强度较低的紫外波段，降低了热辐射干扰。本课题首先开展温度对钆离子光谱性质影响规律研究，包括激发态能级有效布局方式研究、温度对荧光辐射强度以及能级辐射性质影响规律研究。其次，利用钆离子锐线状光谱分布的结构特点，进一步探索热耦合能级对的能级间隔大小、光谱重叠程度、温度等因素与能级热耦合程度的关系，寻找减小非玻尔兹曼分布参数的有效途径。本课题的研究成果，将解决这些长期困扰荧光温度传感领域的难题，为荧光温度传感开辟更广阔的应用领域。

Optical thermometer based on the temperature dependent fluorescence intensity ratio of rare earth ions lends itself to high accuracy contactless temperature measurement. However, its application is limited due to the problems such as luminescence quenching, thermal radiation interference, and non Boltzmann distribution parameter. To solve those problems, we proposed the temperature sensing using temperature dependence of fluorescence intensity ratio of 6PJ levels from Gd3+ ion. The advantages of using Gd3+ ion as temperature sensing active ions include two points. First, the wide band range of Gd3+ ion could reduce the nonradiative relaxation process to the ground state, and thus the luminescence quenching is decreased. Second, the luminescence of Gd3+ ion locates in UV range, leading to reduction of thermal radiation interference. Two research categories are included in this proposal. The effects of temperature on the luminescence properties of Gd3+ ion was first studied, including effective population method of the excited states, the variation of the luminescence intensities and radiative properties with temperature increasing. Further, sharply spiked emission spectra of Gd3+ ions could be utilized to investigate the connections of energy level gap, overlap of fluorescence peaks, temperature and thermally coupling degree, and then to explore an effective way to eliminate non Boltzmann distribution parameter. Besides a solution to those perennial problems, the research results would promote the development of optical thermometry.