Boston Chapter of the IEEE Photonics Society

Wed
Oct 26, 2005
7:00 PM
 

MIT Lincoln Laboratory
 

Generating, Guiding, and Detecting Terahertz Radiation

Dr. Jason Deibel, Rice University, Houston, TX

Abstract:  The terahertz (THz) region of the electromagnetic spectrum (100 GHz to 10 THz) remained relatively unexplored until developments in  ultra fast laser technology provided techniques for the generation and detection of THz radiation. As most dielectric materials are transparent at these frequencies and metals are opaque, there has been considerable interest in developing THz technology as an imaging technique for biomedical, industry, and security applications. The high temporal resolution and broad fractional bandwidth associated with THz radiation has also generated interest within the spectroscopy community.  In order to develop applications based on terahertz technology, attention must be devoted to several basic yet integral aspects of working with radiation in this regime.  During this workshop session, methods for the generation and detection of terahertz radiation will be covered, including the use of photoconductive antennas, electro-optic materials, and semiconductors.   We will also briefly focus on my own research in terahertz emission spectroscopy which is not only an effective method of testing novel terahertz sources, but it is also is an effective tool for investigating the various mechanisms responsible for terahertz generation and for characterizing material properties.   The second half of the session will be spent discussing the guided propagation of terahertz waves.  The development of terahertz waveguides has been stymied by the difficulty in finding a structure and material that exhibits low loss and dispersion at terahertz frequencies. Recently, our group at Rice University showed that simple metal wires  could be effective terahertz waveguides that exhibit very low loss and dispersion. Using this method, the very first terahertz endoscope was developed and demonstrated. Along with these results, I will present Finite Element Method (FEM) simulation results of the propagation of terahertz waves along metal wires.

Biography:  Jason A. Deibel received the B.A. degree in both physics (with honors) and mathematics with a history minor from Transylvania University, Lexington, KY in 1997, and the Ph.D. degree in applied physics from the University of Michigan, Ann Arbor, MI in 2004. His dissertation focused on the use of nonlinear optical polymers in ultrafast electro-optic sampling measurements.  He is currently a post-doctoral Research Associate in the Department of Electrical and Computer Engineering at Rice University, Houston, TX, working with Professor Daniel Mittleman on various aspects of terahertz imaging and spectroscopy. His research interests include terahertz emission spectroscopy of novel inorganic and organic semiconductors, photoconductive antenna design, and finite element method simulations of terahertz guided wave propagation.  Dr. Deibel is a member of the Optical Society of America and the IEEE Lasers and Electro-Optics Society and is currently a Director of Central Intelligence Postdoctoral Fellow.