Super-Resolution Imaging by Metamaterial-Assisted Illumination
This thesis presents theoretical and experimental demonstrations of using hyperbolic metamaterial illumination to go beyond the diffraction limit of optical microscopy. This technique, named as metamaterial assisted illumination nanoscope (MAIN), combines near-field patterned illumination generated by hyperbolic metamaterial (HMM) and far-field detection of an optical microscope to achieve super-resolution. A few designs of hyperbolic metamaterial to projects series of sub-wavelength patterned illumination, as well as a few optical detection configurations, are studied.
An ideal HMM that is homogenous and highly-dispersive is studied by simulation. By implementing well-designed nanostructures, the HMM is capable to project a series of near-field wavelength-dependent patterns with ultrahigh resolution. Those patterns are then utilized to imaging an object by a compressive sensing single pixel imager configuration in which 12 nm resolution is numerically demonstrated.
A practical HMM, consisting of composite Ag-SiO2 multilayers, is studied in experiment. The dispersion property and resolution-limit of such a multilayer HMM are experimentally measured. The HMM shapes the beam into a thin line which can be scanned laterally by tuning wavelength. Proof-of-concept experiment demonstrates the super-resolution capability of MAIN and 80 nm resolution along one dimension of a 2D image is presented.
By replacing the line-illumination to speckle-illumination at near field of the HMM, Speckle-MAIN can achieve 2D super-resolution. Speckle-MAIN prototypes a super-resolution microscope down to 50 nm with a metamaterial substrate and a low-cost, easy-implemented optical system.