Sensor Fusion in Luminescence Thermometry: A Path to Higher Precision and Broader Applicability

Abstract Advancing measurement precision and extending the temperature range are key goals in luminescence thermometry. Traditional single‐parameter methods often underperform. Sensor fusion (SF), a statistical tool widely used in fields like autonomous vehicles and medical imaging, is applied to luminescent thermometry by combining multiple sensor probes or treating each temperature‐dependent parameter as a separate sensor. This approach consistently enhances precision and extends the temperature range, with fused precision equaling the sum of individual precisions. SF using inverse variance weighting surpasses traditional linear regression models due to its adaptability, achieving maximum performance with any sensor material. It works with both time‐resolved and steady‐state readouts, using single or multiple excitation sources. Computer simulations and experiments validate this method. For Sm 2+ , combining lifetime and intensity ratio measurements significantly improves precision across the entire range. Fusion of Mn 4+ , Ho 3+ , and Cr 3+ lifetimes expands the temperature range to 300–650 K. For Yb 3+ /Er 3+ upconversion green and red emission lifetimes, precision improves across all temperatures. However, Mn 5+ shows limited improvement due to the dominance of precision in line‐shift measurements, highlighting a limitation of the approach. Overall, SF demonstrates its potential to revolutionize luminescence thermometry by enhancing precision and usability across diverse conditions.