Speaker: Belkıs Gökbulut


Date/Time: 4 November 2020/ 1:40 - 2:30 pm

Zoom: Meeting ID: 964 4725 8504

Passcode: 964 4725 8504

Abstract: In this talk, light‒matter interaction in several novel photonic platforms will be introduced. Firstly, a simple leaky-mode wedge-type photonic nanocavity is proposed for the inhibition of spontaneous light emission of the CdTe/CdS quantum dots (QDs) by enforcing the suppression of optical modes under the weak coupling regime. Thus, for the first time, the inhibited spontaneous emission rate is achieved using a low Q-factor photonic structure. Secondly, a fluorescence lifetime imaging technique is employed to investigate the spontaneous transition rate of the dye molecules, which are doped in a single PEG nanofiber. The spontaneous emission rate of the confined dye molecules is observed to inhibit and enhance periodically upon swelling of the nanofiber through its exposure to relative humidity, suggesting an efficient optical switching mechanism. In the third photonic platform, the critical role of the confined hybrid mode in a CdTe QDs-doped single nanofiber, which is partially decorated by gold nanoparticles, on the modification of the spontaneous emission dynamics of the fluorescent emitters in a low Q-factor photonic-plasmonic nanocavity is explored for the first time. This is followed by chemically growing hollow cylindrical nanocavities on the surface of a single polymer microfiber, which is uniformly doped with perovskite nanowires; the assembly is employed for the localization of light to meaningfully alter the emission rate of the fluorescent nanowires; due to interaction of the electromagnetic field of the whispering gallery modes, supported by the microfiber, with the boundaries of the cylindrical hollow nanocavities. Finally, a quasi-optical cavity, originating from the transverse Anderson localization of the light waves in an entirely three-dimensional disordered medium, formed by polymer medium with randomly positioned air bubbles, is realized as an alternative to conventional photonic cavities for the intense light localization to strongly enhance the spontaneous emission rate of the fluorescent emitters.

Bio: Dr Belkis Gökbulut graduated from Yeditepe University, Physics Department, in 2012. She obtained both her MSc and PhD degrees in the area of photonics from Boğaziçi University, Physics Department, in 2015 and 2020, respectively. Her PhD thesis was on the light‒matter interaction in photonic nanostructures and was honoured with 2020 Boğaziçi University PhD Thesis Award. She has been working as a postdoctoral research fellow at the same university. Her research involves the following areas: Nanophotonics, nanoplasmonics, light-matter interaction in high and low-Q hybrid nanosystems, random lasers, photonic crystals, cavity quantum electrodynamics in Anderson localized media, time-resolved imaging and spectroscopy of nanosystems and their sensor applications for technological lightwave devices.