Sizing of individual particles with nanoscale precision is crucial for the understanding of their physical and chemical properties and for their use in nanodevices. Optical characterization methods are rapid, non-invasive and may provide a wide range of useful information. However, the weak optical response of subwavelength wide-gap dielectric nanoparticles poses a fundamental challenge for their optical metrology. We demonstrate scalable optical sizing of nanodiamonds based on confocal scanning microscopy. The method is absolutely calibrated by an atomic force microscope and paves the way for the facile metrology of a wide range of weakly scattering nano-objects for applications in biomedicine, catalysis, nanotechnology, and quantum optics.
|