Wireless Near-Field Microwave Imaging Based On Charge State Switching Of NV Centers In Nanodiamonds

Spencer Chuang^1*, Jen-Kai Wu², Y.-P. Hsieh³, M.S. Chang³, Y.H. Chang², M. Hofmann²

¹Graduate Institute of Applied Physics, Nation Taiwan University, Taipei 106, Taiwan
²Department of Physics, Nation Taiwan University, Taipei 106, Taiwan
³Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 115, Taiwan

* Presenter:Spencer Chuang, email:spencer90235@msn.com

We demonstrate a technique for remote microwave(MW) detection based on a unexpected interaction effect between light and microwave intensity in nitrogen-vacancy centers (NV centers) of nanodiamonds(NDs). The presence of surface effects in nanometer-scaled diamond particles was found to control the emission properties of NV centers compared to the commonly investigated bulk NV centers resulting in a pronounced difference in the emission spectrum. The presence of dark states provides new relaxation pathways for excited electrons that are sensitive to the intensity of the microwave radiation and thus result in a quenching of the NV photoemission by up to 95% which has not been observed for bulk specimen.
This novel physical effect provides a sensitive and reliable route to detect microwave signals without the need for electrical connection. A detailed characterization of this remote microwave sensor shows high performance and the ability to reconstruct the microwave power independent of light intensity. The potential of our approach was demonstrated by mapping out the near field distribution of a perforated metal film with submicrometer resolution.

Keywords: NV center, nanodiamond, microwave imaging, microwave sensor