Detection Of Nanowatt Microwave Radiation By The Photoluminescence Of An Ensemble Of Negatively Charged Nitrogen Vacancies In Diamond

We report on detecting continuous 60-GHz microwave radiation with powers in the nanowatt range by the photoluminescence of an ensemble of negatively charged nitrogen vacancy (NV-) centers in diamond at room temperature. The high contrast of the optically detected magnetic resonance and the efficient photon collection yield a magnetic field sensitivity of 86 nT/root Hz for continuous-wave laser excitation with a photon energy of 2.33 eV and a power density of 93 W/cm(2). The efficiency of the microwave-power-to-magnetic-field conversion amounts to 0.54 mT/root W. The microwave excitation also enhances the degree of the linear polarization of NV- photoluminescence at magnetic resonance conditions, and for linearly co-polarized NV- photoluminescence and laser light, the magnetic field sensitivity is improved by about 7%. Published by AIP Publishing.