Nanoscale optical tomography

About

Abstracts: Stanford researchers have developed a novel tomographic technique, cathodoluminescence (CL) spectroscopic tomography, to probe optical properties in 3D with nanometer-scale spatial and spectral resolution. These tomograms can locate regions of efficient cathodoluminescence across visible and near- infrared wavelengths in three dimensions, with contributions from material luminescence and radiative decay of electromagnetic eigenmodes.  This CL tomography technique has been demonstrated by reconstructing a 3D metal-dielectric metamaterial resonator, illustrating how the technique can be applied to almost any materials system to achieve label-free, nanoscale 3D visualization of light-matter interactions.   Stage of Research: Proof-of-concept – Successfully demonstrated use of CL tomography to achieve nanoscale 3D visualization of light–matter interactions by reconstructing a three-dimensional metal–dielectric nanoresonator Applications: In photovoltaics, may enable determination of the 3D distribution of defect states In light emitting diodes or other semiconductor-based devices, will allow 3D visualization of radiative recombination centers In bio-imaging, may enable label-free 3D imaging of nanostructures   Advantages: 3D Imaging - Image radiative optical properties with nanoscale spatial and spectral resolution in 3D High resolution afforded by cathodoluminescence combined with 3D imaging capabilities enabled by tomographic reconstruction Resolution at least 10-100 times better than the diffraction limit Simple computational methods for reconstruction Does not require labels (i.e. fluorescent molecules used in conventional super-resolution biological imaging) Improvements over STEM EELS tomography: Signal is fundamentally different/complementary Higher spectral resolution SEM -> wider range of samples, cheaper instrumentation