Developments in nanoscience, biotechnology and photonics are on the verge of offering great opportunities for the exploration of optical interactions at the nanoscale. Today, there is an ever-increasing need for optical imaging tools that are able to resolve features at the length-scales relevant for biological cells, molecules, and complexes, as well as for the rapidly developing class of materials known as nanostructures. Addressing this need, this groundbreaking book serves as a one-stop review of modern nano-optical and nano-imaging techniques, applications, and developments. It focuses on near-field microscopy which has opened up optical processes at the nanoscale for direct inspection. This frontline resource helps researchers and engineers achieve high resolution optical imaging of biological species and functional materials. The book also offers detailed coverage of the imaging of optical device operation and new nanophotonics functionalities.