Structured illumination microscopy using extraordinary transmission through sub-wavelength hole-arrays

A new microscopy method for multi diffraction-limited spot illumination is based on extraordinary light transmission through a periodic metal grid (typical period of 600 nm) of sub-wavelength holes (150 nm). Multiple spots illuminate a fluorescently labeled sample and the emission is collected by far-field optics. Theoretical comparison with a confocal microscope reveals equivalent spot sizes and a scanning method with the advantage of multiple illumination spots. The system is used to measure the actual transmitted field with a fluorescent sample in far-field. The obtained results are consistent with the theoretical prediction and provide a proof of concept of the midfield microscope.