Subwavelength imaging via dark state

We theoretically study possibilities of creating spatial patterns having subwavelength length by using so-called dark states. These dark states are formed via interaction with bichromatic optical fields. Performing experiments in Rb vapor, we experimentally demonstrated spatial patterns that are smaller than the length determined by the diffraction limit of optical system used in the experiment. This approach has applications to interference lithography and can be used in coherent Raman spectroscopy to reach subwavelength spatial resolution.