(635b) Resonance Imaging Microscopy: Breaking the Diffraction Limit with Visible Light

Motivated by the need to visualise anisotropic nanoparticles in the formation of engineered coatings and dynamic processes in life sciences, we have developed a new imaging modality not limited by the diffraction limit using visible light, called Resonance Imaging Microscopy (RIM). We describe this multi-source evanescent field scattering technique to enable high-speed, non-destructive, label and stain-free imaging of particulates with nearly any shape and composition, ranging in size from hundreds of microns to tens of nanometres. We simultaneously or sequentially record the spatially correlated scattering of multiple evanescent waves, generated via laser light sources, from individual particles or objects of arbitrary shape, and use this data to reconstruct size or shape of the particle. We discuss the physical principles behind this method as well as results of modelling the scattering behaviour using generalised Lorentz Mie theory. We then describe both direct and statistical results validating the fidelity of geometric measurements for a selection of spherical calibration particles with radii spanning four orders of magnitude. We outline a variety of different methods for implementing this technique with increasing ease of use for the users. We also demonstrate imaging and measurement of a diverse range of particulates including nanospheres, nanotubes/rods, mineral powders and various biological materials. In addition to particle metrology applications, this technique will be especially useful in the life sciences for in situ imaging and measurement of delicate or transient biological systems under ambient conditions.