Subnanoscale resolution for microscopy via coherent population trapping.

We present a coherent-population-trapping-based scheme to attain subnanoscale resolution for microscopy. We use three-level atoms coupled to an amplitude modulated probe field and a spatially dependent (standing-wave or Laguerre-Gaussian) coupling field. The probe field modulation allows us to tap into the steep dispersion normally associated with electromagnetically induced transparency and offers subnanometer resolution using optical fields.