Presented by Roman Sobolewski, Departments of Electrical and Computer Engineering and Physics and Astronomy, the Materials Science Graduate Program, and the Laboratory for Laser Energetics
Abstract: The field of THz science and technology is still in its infancy, but has already gained a very large international interest due to its numerous applications ranging from ultrahigh-speed communication systems to medical imaging and diagnostics, industrial quality control, and security screening. In conventional terms, we can talk about the “THz gap,” i.e., a region of electromagnetic radiation spectrum where it is very difficult to successfully operate either electronic or photonic “classical” devices. For even the fastest FET-type transistor structures, the THz frequency of operation is extremely high, while for optics the THz radiation wavelength is far too long since THz quanta have the energy much smaller than the thermal background energy at room temperature. We present here a novel, integrated-optoelectronics approach that combines femtosecond laser pulses with materials and devices exhibiting sub-picosecond photo response times.
We review our Ultrafast Quantum Phenomena Laboratory current THz photonics research, aimed towards generation and subsequent detection of sub-picosecond electrical transients for time-resolved (THz-bandwidth) studies of novel materials and nanostructured devices. Our free-space THz spectroscopy setup is characterized by the operational frequency bandwidth of up to 5 THz and is very well suited for noninvasive tests of various chemical compounds and biological materials. As examples, we present a time-resolved characterization of a novel, spintronic emitters of THz transients based on the inverse spin Hall effect; femtosecond spectroscopy studies of graphene nano-flakes embedded in a polymer medium, forming a nanocomposite with the 1% graphene content, as well as THz imaging of biomaterials, specifically, ex-vivo imaging of mouse pancreatic normal and tumor tissues. Future prospects of THz photonics will complete our presentation
Roman Sobolewski is a Professor of Electrical and Computer Engineering, Physics, and Materials Science, as well as a Senior Scientist of Laser Energetics at the University of Rochester (UR), Rochester, NY, USA. At the UR Laboratory for Laser Energetics, he is the Head of the Ultrafast Quantum Phenomena Laboratory.
Wednesday, March 10 at 12:00pm to 1:00pmVirtual Event