Ultrasensitive Diagnostic Analysis of Au Nanoparticles Optically Trapped in Silicon Photonic Circuits at Sub-Milliwatt Powers

Silicon
microcavity-based optical trapping of Au nanoparticles
with diameters as small as ≈24 nm is achieved using optical
powers <1 mW. By comparing measured and modeled histograms of transmission
time series data obtained when a particle is trapped in the cavity,
it is shown that the influence of backaction on the transmitted light
dynamics alone can be used to determine the size of trapped particles
with nanometer precision.