Laser Scanning Microscopy of superconducting electromagnetic metamaterials

Sub-wavelength superconducting rf meta-materials have evident advantages over their normal metal counterparts for strong diamagnetism, low-loss and intrinsically nonlinear tunability with temperature, dc magnetic, and rf electromagnetic field. These microwave properties are uniquely controlled through the spatial distribution of super-fluid density in the superconductor. The technique of low-temperature Laser Scanning Microscopy (LSM) is applied to investigate local contribution of these effects onto global rf response of superconducting meta-materials having different geometry of artificially structured magnetic meta-atoms. The main capabilities of the LSM technique for noncontact spatially resolved characterization of such structures are reviewed.