Spectro-Temporal Ratiometric Strategy for Thermally Invariant Optical Manometry

Optical manometry provides noncontact pressure sensing but remains vulnerable to temperature-induced drift, where thermal expansion and nonradiative relaxation distort luminescence spectra and kinetics. We develop a spectro-temporal ratiometric approach that combines spectral and time-gated luminescence channels to decouple pressure and temperature responses and realize thermally invariant optical manometry. Using Y₃In₂Ga₃O₁₂:Cr³⁺ as a rigid-lattice host (D_q/B ≈ 2.2), lattice stiffness minimizes thermal sensitivity S_R,T, while ratiometric detection stabilizes pressure sensitivity S_R,p. The resulting thermal-invariance manometric factor (TIMF) = S_R,p/S_R,T reaches ≈7700 K·GPa^-1 in the spectral domain and ≈2500 K·GPa^-1 in the time-gated domain, with S_R,p up to 51%·GPa^-1. These values exceed ruby benchmarks by two orders of magnitude and surpass conventional lifetime analysis by ∼40 times, enabling accurate, self-referenced optical pressure mapping under extreme thermo-mechanical conditions. This work provides luminescent manometry from empirical calibration to a quantitative framework for thermally reliable sensing in coupled fields.