Why not use the thermal radiation for nanothermometry?

TL;DR

This paper discusses the limitations of using thermal radiation spectroscopy for nanothermometry, highlighting issues like power loss and poor spatial resolution that hinder its effectiveness at the nanoscale.

Contribution

The paper critically analyzes the challenges of applying thermal radiation for nanothermometry and explains why it is currently unsuitable for high-resolution temperature measurements.

Findings

Thermal radiation spectroscopy faces power loss issues in near surroundings.

It has poor spatial resolution at the nanoscale.

Current techniques are limited by low sensitivity and fluorescence fluctuations.

Abstract

The measurement of temperature with nanoscale spatial resolution is an emerging new technology and it has important impact in various fields. An ideal nanothermometer should not only be accurate, but also applicable over a wide temperature range and under diverse conditions. Furthermore, the measurement time should be short enough to follow the evolution of the system. However, many of the existing techniques are limited by drawbacks such as low sensitivity and fluctuations of fluorescence. Therefore, Plank's law offers an appealing relation between the absolute temperature of the system under interrogation and the thermal spectrum. Despite this, thermal radiation spectroscopy is unsuitable for far-field nanothermometry, primarily because of the power loss in the near surroundings and a poor spatial resolution.