Dual electro-optic frequency comb photonic thermometry

We report a precision realization of photonic thermometry using dual-comb spectroscopy to interrogate a $\pi$-phase-shifted fiber Bragg grating. We achieve read-out stability of 7.5 mK at 1 s and resolve temperature changes of similar magnitude--sufficient for most industrial applications. Our dual-comb approach enables rapid sensing of dynamic temperature, and our scalable and reconfigurable electro-optic generation scheme enables a broad sensing range without laser tuning. Reproducibility on the International Temperature Scale of 1990 is tested, and ultimately limited by the frequency reference and check-thermometer stability. Our demonstration opens the door for a universal interrogator deployable to multiple photonic devices in parallel. Applications include on-chip measurements to simultaneously evaluate quantities like temperature, pressure, humidity, magnetic field and radiation dose.