Vector-Field Nonlinear Microscopy of Nanostructures

Microscopic techniques based on nonlinear optical processes provide alternative ways to visualize natural and artificial nanoscopic systems with minimum disturbance. In such techniques, each nonlinear process provides its own contrast mechanism and thus sensitivity to different sample properties. Powered by the mutual developments in instrumentation and theoretical descriptions, the capabilities of nonlinear microscopy have significantly increased in the past two decades. In addition, the vectorial focusing properties of conventional (for example, linear and circular) and unconventional (for example, radial and azimuthal) light polarizations are providing new capabilities for nonlinear microscopy, while simultaneously requiring new approaches in the interpretation of the acquired data. In this review article, we discuss the principles of nonlinear microscopy with vector fields and how its unique properties have recently characterization of various types of nanostructures.