Ultrafast Optoelectronics for Broad Bandwidth Microwave Measurements of Materials

Middle Tennessee State University, Murfreesboro TN

Investigators

Abstract

The proposal supports research in broad bandwidth microwave/millimeter-wave measurements of materials using the Ultrafast Optoelectronics Laser Laboratory (UOLL) at Middle Tennessee State University. The UOLL centers around a Terahertz measurement system based on photoconductive antennas which are driven by a mode-locked Ti:sapphire laser. The antenna structures for the proposed research are designed to emit polarized, directional radiation over the frequency range 10 GHz to 200 GHz; a frequency range of growing technological interest and one in which few other broad bandwidth sources exist. There are two research focus areas. (1) Measure the microwave properties of photonic band gap materials, in particular determine the dispersion relations of bulk and surface electromagnetic modes in dielectric and metallo-dielectric arrays. (2) Demonstrate the use of broad bandwidth microwave ellipsometry as a non-contact method for determining the microwave dielectric constant and loss of thin films on semiconducting substrates. This proposal is submitted under the NSF's Research in Undergraduate Institutions (RUI) program. A number of factors contribute to the value of this research program for undergraduates. Because this optoelectronic technique is not widely practiced it is easy to frame a number of research projects that can be partitioned into segments which can be accomplished in the time frame available to undergraduate students. The science is accessible and incorporates and reinforces topics covered in the modern undergraduate physics curriculum (particularly electrodynamics, solid state physics, Fourier methods, and optics). Finally, the students develop technologically relevant experimental skills in optics and lasers, electronics, semiconductors, and thin films.