Emerging technologies in the field of thermometry

Abstract The past decade saw the emergence of new temperature sensors that have the potential to disrupt a century-old measurement infrastructure based on resistance thermometry. In this review we present an overview of emerging technologies that are either in the earliest stages of metrological assessment or in the earliest stages of commercial development and thus merit further consideration by the measurement community. The following emerging technologies are reviewed: Johnson noise thermometry, optical refractive-index gas thermometry, Doppler line broadening thermometry, optomechanical thermometry, fiber-coupled phosphor thermometry, fiber-optic thermometry based on Rayleigh, Brillouin and Raman scattering, fiber-Bragg-grating thermometry, Bragg-waveguide-grating thermometry, ring-resonator thermometry, and photonic-crystal-cavity thermometry. For each emerging technology, we explain the working principle, highlight the best known performance, list advantages and drawbacks of the new temperature sensor and present possibilities for future developments.