Temperature dependence of nitrogen-vacancy center ensembles in diamond based on an optical fiber

TL;DR

This study investigates how the zero-field splitting parameter of NV centers in diamond varies with temperature, demonstrating a fiber-based sensing method with high accuracy from 298.15 K to 383.15 K.

Contribution

It introduces a fiber-integrated NV center sensor for temperature measurement and provides detailed analysis of temperature dependence with improved accuracy.

Findings

Measured D and T with standard uncertainties of 3.6e-5 GHz and 0.3 K.

Results consistent with previous studies and theoretical extrapolations.

D-T relationship varies with NV concentration and manufacturing processes.

Abstract

The nitrogen-vacancy (NV) centers in diamond sensing has been considered to be a promising micro-nano scale thermometer due to its high stability, good temperature resolution and integration. In this work, we fabricated the sensing core by attaching a diamond plate containing NV centers to the section of a cut-off multi-mode fiber. Then we measured the zero-field splitting parameter (D) of NV center ensembles using continuous-wave optical detected magnetic resonance (CW-ODMR) technique. A home-made thermostatic system and two calibrated platinum resistance thermometers were applied for reference temperature measurement. The effects from preparation time and count time in the pulse sequence, laser power, microwave power, and microwave frequency step were investigated. Moreover, the experimental D and T from 298.15 K to 383.15 K was obtained with the standard uncertainty of u(D) = (3.62268~8.54464)x10^-5 GHz and u(T) = (0.013~ 0.311) K. The experimental results are well consistent with the work of Toyli, et al. (Toyli, et al., 2012) using the similar diamond sample. The extrapolation for D-T at 0 K and 700 K also agree with other references, and meanwhile dD/dT varies with temperature. Finally, comparing the D-T relationship measured by different research groups, we can know that the NV concentration resulting in different electron density and manufacturing procedure resulting in different thermal expansion would lead to different D-T relationship. It is worthy to continue further comprehensive research especially from the metrological point of view to develop NV center as a practical and accurate micro-nano scale thermometry.