  Using light to non-destructively detect nanoscale perturbations is vital to
many fields including material characterization, human disease diagnosis, and
semiconductor electronics. In this work, we introduce the concepts of
electromagnetic canyons and non-resonance amplification and apply them on a
conventional diffraction-limited optical microscope to directly view individual
perturbations (25-nm radius = wavelength/31) in a nanoscale volume. Considering
the extensive impact of microscopy on scientific discovery and technology
development, our noninvasive imaging-based method with deep subwavelength
footprint will have far-reaching consequences that will affect our everyday
lives.
