Optimization of the sensitivity of a temperature sensor based on germanium-vacancy color center (GeV) in diamond

TL;DR

This paper compares two methods for temperature sensing using GeV color centers in diamond, demonstrating that the new ratio-based approach offers nearly double the sensitivity at high temperatures while maintaining simplicity and cost-effectiveness.

Contribution

The paper provides a detailed comparison of spectral and ratio-based methods for GeV diamond temperature sensors, highlighting the improved high-temperature sensitivity of the new approach.

Findings

At room temperature, both methods perform similarly.

At 300°C, the ratio method nearly doubles the sensitivity.

Optimal filter parameters are crucial for maximum performance.

Abstract

Temperature sensors based on the GeV color center in diamond are gaining considerable attention in both scientific and industrial fields. For widespread industrial adoption, however, these sensors need a design that is as simple and cost-effective as possible. The original sensor design relied on measuring the spectral characteristics of the zero-phonon line. Recently, a modified approach was introduced, which involves splitting the GeV emission with a dichroic mirror and determining temperature based on the ratio of the two resulting signals. In this analysis, we provide a detailed comparison of both methods. At room temperature, the two methods show comparable performance, with slight variations depending on component quality. However, at temperatures around 300 {\deg}C, the new method's performance is estimated to be nearly twice that of the original, provided optimal filter parameters are used. Additionally, the sensitivity of the new method remains roughly consistent with its performance at room temperature.