If you are interested, please send your application (CV and motivation letter) either to Dr. Agnese Callegari (callegari@fen.bilkent.edu.tr) or to Dr. Sabareesh K. P. Velu (sabareesh@fen.bilkent.edu.tr)
The photonic force microscope (PFM) can measure femtonewton and piconewton forces. Using a PFM we performed the first measurement of surface plasmon radiation forces. We have also extended the PFM potential to the characterization of rotational force fields, with applications, e.g., in microfluidics. [ read more ]
Total internal reflection microscopy (TIRM) is a sensitive non-invasive technique to measure the interaction potentials between a colloidal particle and a wall with femtonewton resolution. Our work has largely extended the range of conditions accessible with TIRM, e.g. gold coated surfaces or large penetration depths. [ read more ]
The ineluctable presence of thermal noise alters the measurement of forces acting on microscopic and nanoscopic objects, such as biomolecules and nanodevices. Our results demonstrate that the force-measurement process is prone to artifacts if the noise is not correctly taken into account. Our results are intimately connected to the long-standing issue of the interpretation of multiplicative noise in stochastic differential equations (Ito-Stratonovic dilemma). [ read more ]
We reported the first experimental observation of momentum transfer from a surface plasmon to a single dielectric sphere. We showed that the force magnitude at resonance gets strongly enhanced compared to a nonresonant illumination. We are also studying the possibilities of fractal plasmonics. [ read more ]