Optical properties of nanostructures strongly depend on their size, shape, material, and local environment. To fully characterise these properties, measurements of the full spectral response are required . The initial challenge is due to the small response of a nanoparticle in an optical field, the extinction. This can be overcome by using interferometry where the field scattered from the nanoparticle is multiplied by a larger reference field. This thesis aims to investigate the use of a broad band supercontinuum source for interferometric detection of single nanostructures.