Polarization-Resolved Optical Metrology for Noncontact Thermometry

Noncontact temperature measurements with large (thermal) dynamic range are desirable in many applications. Aside from interferometric techniques, fluorescence intensity and spectral shape have been exploited in the past for sensitive thermometry in luminescent materials. Here, we present a novel method that utilizes the polarization-sensitive reflection and/or transmission of light from (through) an optical material without relying on any fluorescence. A balanced photodetector will measure the difference signal corresponding to two orthogonal polarization states with high singal-to-noise ratio. Temperature resolution of 5 mK have been demonstrated.