Super-resolution Spatial Frequency Differentiation of Nanoscale   Particles with a Vibrating Nanograting
  We propose a scheme for detecting and differentiating deeply subwavelength particles based on their spatial features. Our approach combines scattering from an ultrasonically modulated nanopatterend grating with heterodyne techniques to enable far-field detection of high spatial frequency Fourier components. Our system is sensitive to spatial features commensurate in size to the patterning scale of the grating. We solve the scattering problem in Born approximation and illustrate the dependence of the signal amplitude at modulation frequency on grating period, which allows to differentiate between model nanoparticles of size $\lambda/20$. 
Leonid Alekseyev, Evgenii Narimanov, Jacob Khurgin
physics.optics cond-mat.mes-hall