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Laser threshold magnetometry

MetadataDetails
Publication Date2016-01-08
JournalNew Journal of Physics
AuthorsJan Jeske, Jared H. Cole, Andrew D Greentree, Jan Jeske, Jared H. Cole
InstitutionsARC Centre for Nanoscale BioPhotonics, RMIT University
Citations51

We propose a new type of sensor, which uses diamond containing the optically\nactive nitrogen-vacancy (NV$^-$) centres as a laser medium. The magnetometer\ncan be operated at room-temperature and generates light that can be readily\nfibre coupled, thereby permitting use in industrial applications and remote\nsensing. By combining laser pumping with a radio-frequency Rabi-drive field, an\nexternal magnetic field changes the fluorescence of the NV$^-$ centres. We use\nthis change in fluorescence level to push the laser above threshold, turning it\non with an intensity controlled by the external magnetic field, which provides\na coherent amplification of the readout signal with very high contrast. This\nmechanism is qualitatively different from conventional NV$^-$—based\nmagnetometers which use fluorescence measurements, based on incoherent photon\nemission. We term our approach laser threshold magnetometry (LTM). We predict\nthat an NV$^-$—based laser threshold magnetometer with a volume of 1mm$^3$ can\nachieve shot-noise limited d.c.~sensitivity of 1.86 fT$/\sqrt{\rm{Hz}}$ and\na.c.~sensitivity of 3.97fT$/\sqrt{\rm{Hz}}$.\n