Light-matter interaction in the nanoscale: a case for THz near-field spectroscopy
Speaker: Mr Xiao Guo
Host: Prof Aleks Rakić
Seminar Type: PhD Confirmation Seminar
Abstract:
Over the past 25 years, Terahertz (THz) radiation has been of major interests with a multitude of applications being investigated including, material characterization, tissue classification, identification of pharmaceutical components, food quality assurance, art conservation and homeland security. The long wavelength (1 THz_300 mm) limits most THz investigations to samples with features on the order of a few hundreds of micrometers. To study materials/structures with nano-scale spatial variations, one must find a way to break the diffraction limit. Scanning near-field optical microscopy (SNOM), offers one solutions allowing imaging and spectroscopy in the THz regime with spatial resolution of a few hundred nanometres. This project aims to explore the interaction of THz radiation with matter in the nanoscale using a scattering-type SNOM (s-SNOM) to qualitatively and quantitatively investigate samples of interest. The extraction of optical material properties from near-field scattering signals will provide the new insight into the properties of a wide range of organic and inorganic materials, structures, biological tissues (including skin and cartilage), and other multilayer structures.
Biography:
Xiao Guo is a PhD student in the photonics group, ISB Discipline, in the School of Information Technology and Electrical Engineering at the University of Queensland. His supervisors are Prof. Aleksandar D. Rakić and Dr. Karl Bertling. Xiao Guo received his BSc in Applied Physics from Northeastern University in 2017 and received his M.Sc. (Electrical and Electronic Engineering) from the University of Hong Kong in 2018. His research interests include near-field imaging and spectroscopy analysis, light-matter interaction. His research work focuses on quantitative analysis of nanoscale Terahertz light-matter response on inorganic and organic samples.