Multi-parameter temperature prediction based on optical fiber filled with CsPbX3 QDs

To expand the range of application of quantum dots in the field of temperature sensing, this paper proposed three kinds of temperature sensors based on CsPbX3 (X = Br, Br/I, and I) quantum dots filling into hollow-core fibers. Based on the photoluminescence properties of quantum dots, quantum dots were prepared by the hydrothermal method and later filled in hollow-core optical fibers to fabricate three kinds of temperature sensors. In this paper, the temperature dependence of photoluminescence of quantum dot sensors has been studied. In detail, temperature variation characteristics of integrated photoluminescence, full width at half maximum, and central wavelength of the photoluminescence spectrum have been investigated. It is found that the integrated photoluminescence, full width at half maximum, and central wavelength all fluctuate regularly with temperature. In this paper, the support vector regression method is employed to determine the mathematical relation between integrated photoluminescence, full width at half maximum, central wavelength, and temperature. Later, the three parameters are used to achieve fast and accurate temperature measurement. The experimental results show that in the range of 30–100⁡°C, the precision of the optical fiber temperature sensors based on quantum dots is below 2⁡°C.