Research Interests

Terahertz science and technology

Our research involves the use of radiation in the terahertz region of the electromagnetic spectrum.  This range lies between the microwave and infrared, at the boundary between electronics and photonics.  The techniques for generating, manipulating, and detecting terahertz radiation are less mature than those of the microwave, infrared, or visible ranges, although much progress has been made in recent years.  As a result, there are many new opportunities and exciting possibilities in science, technology, and applications.  Our work spans this range, including recent activities in a variety of areas:

Terahertz wireless communications

It is becoming clear that future generations of wireless technology will need to exploit the spectral range between 100 GHz and 1 THz, in order to keep up with the global skyrocketing demand for bandwidth.  However, few of the physical layer components necessary for constructing such a system exist.  As a result, the parameters which will define the system architecture and network protocols remain unclear.  Our group contributes to this fascinating emerging challenge by exploring new device concepts for wave guiding, modulation, multiplexing, beam steering, and wavefront engineering. We have also become involved in test-bed demonstrations of links, for studying the properties of THz wireless channels and investigating the resilience of such links against eavesdropping.

Collaborative: CNS Core: Access, mobility, and security, above 100 GHz

Terahertz spectroscopic studies of condensed matter systems

New techniques for producing very high intensity terahertz pulses have opened the door to a rich array of physical phenomena in this spectral range.  We are exploring the use of these techniques to study novel materials including soft condensed matter systems and complex metal oxides.  In addition, we are pushing the frontiers of spectroscopic techniques with new capabilities for pressure-dependent terahertz spectroscopy. This is of particular relevance in many soft condensed matter and macro-molecular systems, where the low-frequency (THz) vibrational modes are often intimately linked to macroscopic thermodynamic properties such as thermal expansion and Young's modulus. These modes are also often key to the molecular motions which enable functionality, such as the gate-opening modes of metal-organic frameworks.

Terahertz near-field probes

Our group has been interested for some time in techniques for probing materials and imaging surfaces using terahertz fields on a sub-wavelength scale. Several groups have recently demonstrated powerful new tools based on AFM and STM techniques.  We are now developing a terahertz emission microscope which relies on an apertureless near-field tip. This enables simultaneous reflection and emission measurements with sub-100-nanometer resolution. The optical nonlinearity of the emission process is manifested as an effective sharpening of the near-field tip.

 More information about our research can be found here: Group Publications

A few useful THz-related links:

Weekly meeting schedule

Zhaoji 11:30
Rabi 2:30
Hichem 3:00
Yasith 3:30
Angela 4:00