Characterization of laser micro machined terahertz metallic wire waveguides

Abstract

<p>Terahertz radiation, a region of the electromagnetic spectrum which lies in between the microwave and infrared, has gained considerable attention recently due to interesting properties exhibited by materials exposed to this radiation. The uniqueness of the use of THz radiation for sensing and imaging applications lies in the notion that THz is easily transmitted through non-metals. People have witnessed how fiber optics operating in the visible region of the spectrum has brought us closer across the world. A crucial step in the future application of terahertz technology is the development of waveguides that work well at these frequencies. Our present work is to characterize the laser micro-machined metallic waveguides using terahertz time-domain spectroscopy and imaging. The THz pulses emitted at the transmitter excite the surface plasmon polaritons of the metal wave guide and propagate as surface waves that are detected at the receiver end. THz pulses are generated by driving a photoconductive antenna with an ultrafast laser, focused on to the plasmonic lens which produces radially polarized light, in turn coupled to the metal waveguide and detected at the end with another photoconductive antenna. We will continue our work by investigating different geometries of the cylindrical and tapered metal waveguides by varying the diameter and length of the wires and also on the most effective metal to be chosen as the waveguide depending on the conductivity, melting point of various metals and operating conditions. Understand the physics behind mechanisms such as coupling, loss, dispersion, and electric field confinement of these surface waves along the waveguide. The success of this work will replace the complex free space optics used in terahertz systems and also reduce cost.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>