DCMPMS Seminars
Microcavity-enhanced investigation of nanoparticle dynamics
by Mr. SHALOM PALKHIVALA (Karlsruhe Institute of Technology, Germany)
Tuesday, August 16, 2022
from
to
(Asia/Kolkata)
at AG 80
at AG 80
Description |
We have developed a fibre-based high-finesse Fabry-Perot microcavity capable of detecting and characterising single unlabelled nanoparticles. Silica nanospheres with radii of 25 nm and gold nanorods 20 nm in length have thus been detected in water. Properties of the nanospheres such as the size, polarizability and refractive index were deduced, and the three-dimensional Brownian motion of a single nanoparticle in the cavity was tracked with spatial and temporal resolutions as good as 8 nm and 0.3 ms respectively. Furthermore, the rotation of nanoparticles could be measured using the polarisation splitting of the resonance. When cavity scanning is too slow to resolve small dynamic time constants, e.g. the rotation of gold nanorods, measurement using an actively locked cavity can be used to provide a high measurement bandwidth limited only by the detector or the cavity linewidth. This additionally offers the advantages of improved mechanical stability and drift compensation. Based on this, we aim to investigate the optical and dynamic behaviour of single biomolecules, such as DNA. |