Optical Nanoscale Thermometry: From Fundamental Mechanisms to Emerging Practical Applications

Abstract Knowledge of temperature and temperature gradients with nanoscale resolution is critical for a variety of applications in medicine, nanoelectronics, biology, and solid‐state‐based devices. The number of existing nanothermometry techniques is remarkably large, varying for materials, mechanisms, sensitivity, and operating ranges. In this work, a selected group of prominent nanoscale thermosensors is reviewed, which are all‐optical and nanoparticle‐based. Specifically, the focus is on the analysis of their fundamental mechanism to identify absolute, intrinsic capabilities and limitations of each nanothermometry platform. Prominent applications as well as future challenges and opportunities in the field are discussed.