Physics CAMP Seminar
Physics CAMP Seminar
Metal nanoparticles (NPs) sustain a collective oscillation of their free electrons, called a localized surface plasmon resonance (LSPR), when excited by an electromagnetic wave. When this incident wave is resonant with the LSPR frequency, the field intensity is strongly increased in the near field of the NP. Plasmonics thus provides a unique tool for the manipulation and confinement of light well beyond the diffraction limit. This has opened up a wide range of applications based on extreme light concentration, including nanophotonic lasers and amplifiers, biochemical sensing, and optical metamaterials. However, many difficulties remain in experimentally measuring the shape, size, and enhanced field properties of the localized electromagnetic modes in the vicinity of the NPs due to the limitations of optical microscopy. Here, I will discuss how we can unravel the coupling of light to a nano-antenna through single-molecule fluorescence imaging. This technique is a powerful tool to optically study structures beyond the diffraction limit by localizing isolated fluorophores and fitting the emission profile to the microscope point-spread function. By using the random motion of single dye molecules in solution to stochastically scan the surface, and by assessing emission intensity, wavelength, lifetime, and density of emitters as a function of position, we gain new insight into the properties of these systems and pave the way for the development of devices operating at the single photon level.
Bio: Esther Wertz obtained her PhD in Physics in 2010 for the work she did with Dr. Jacqueline Bloch at the CNRS Photonics and Nanostructures Laboratory in France. She did her postdoctoral work with Dr. Julie Biteen at the University of Michigan, then joined the Department of Physics, Applied Physics, & Astronomy at Rensselaer Polytechnic Institute as an Assistant Professor in 2015. She is the recipient of a PicoQuant Young Investigator Award and an NSF CAREER award. Her research at Rensselaer focuses on investigating light-matter interactions in the vicinity of nanostructures using super-resolution microscopy techniques, and on designing structures that interface with light in predetermined ways. She is interested in exploring the new quantum properties that emerge when excitons and localized surface plasmon resonances become strongly coupled.