Guoqing Wang

Conventional contact thermometry can perturb the local thermal field, while infrared thermography primarily probes surface temperature and does not directly provide localized temperature information within transparent fused-silica components. Laser-induced defect fluorescence (LIDF) offers non-contact, coating-free interrogation of a finite volume within fused silica, but compact two-channel implementation requires spectral bands that balance temperature sensitivity and signal uncertainty. We developed an uncertainty-guided method that propagates an empirical noise model through a logarithmic intensity-ratio calibration and ranks feasible band pairs using the 95th-percentile temperature uncertainty. For fused silica calibrated from 300 to 950 K, the optimized bands were centered at 344 and 396 nm with full bandwidths of 20 and 14 nm. The baseline model yielded median uncertainties of 6.47 K and 14.06 K. An interleaved-temperature calibration-sparsity assessment gave an RMSE of 34.00 K when the calibration spacing increased from 50 to 100 K, highlighting the need to consider calibration resolution together with spectral-band optimization in practical two-channel implementation.