A novel fiber optic temperature sensor based on CCT measurement and tipped with a PDMS-YAG:Ce phosphor mixture

This paper presents a novel fiber-optic temperature sensor based on correlated color temperature (CCT) measurement. The sensor is formed by a homogeneous mixture of polydimethylsiloxane (PDMS) and cerium-doped yttrium aluminum garnet (YAG:Ce) phosphor, applied as a tip on the faces of an optical fiber pair. While YAG:Ce phosphors are commonly used in lighting and white light-emitting diode (WLED) technologies, their use in thermoluminescence and temperature sensing has been only minimally explored. We demonstrate that the temperature of a homogeneous PDMS-YAG:Ce mixture can be directly related to its CCT, and a highly linear dependence on temperature was identified across the studied range. The findings confirm that this CCT-based approach enables both contact and non-contact temperature measurement. The proposed optical sensors operate effectively from -60°C to 220°C (213-493 K), and their resistance to electromagnetic radiation was within a magnetic field range of -2 T to 2 T.