Electromagnetically-induced transparency in a diamond spin ensemble enables all-optical electromagnetic field sensing

摘要

We use electromagnetically-induced transparency (EIT) to probe the narrowelectron-spin resonance of nitrogen-vacancy centers in diamond. Working with amulti-pass diamond chip at temperatures 6-30 K, the zero-phonon absorption line(637 nm) exhibits an optical depth of 6 and inhomogenous linewidth of ~30 GHzfull-width-at-half-maximum (FWHM). Simultaneous optical excitation at twofrequencies separated by the ground-state zero-field splitting (2.88 GHz),reveals EIT resonances with a contrast exceeding 6% and FWHM down to 0.4 MHz.The resonances provide an all-optical probe of external electric and magneticfields with a projected photon-shot-noise-limited sensitivity of 0.2V/cm/sqrt(Hz) and 0.1 nT/sqrt(Hz), respectively. Operation of a prototypediamond-EIT magnetometer measures a noise floor of less than 1 nT/sqrt(Hz) forfrequencies above 10 Hz and Allan deviation of 1.3 +/- 1.1 nT for 100 sintervals. The results demonstrate the potential of diamond-EIT devices forapplications ranging from quantum-optical memory to few-photon nonlinearoptics, precision measurement, and tests of fundamental physics.