Morphology-dependent resonances of optical microcavity resonators have shown promise for a range of applications in optical communication including filtering, switching and multiplexing. These optical resonators can be rings, disks or spheres, with sizes ranging from several microns to several hundreds of microns. Due to their ultra-high sensitivity potential, microsphere optical resonators have also been proposed as molecular/biological sensors. Our research program at SMU explores potential applications in mechanical sensing. We recently demonstrated the feasibility of micro-optical sensors for temperature, force, pressure, wall shear stress as well as electric and magnetic fields. The sensors are based on dielectric micro-beads that are excited by coupling light from optical fibers. The technology exploits the morphology-dependent shifts in resonant frequencies that are commonly referred to as the whispering gallery modes (WGM). These optical resonances can possess extremely large quality factors (up to Q~108) allowing for very high sensor resolutions. Further, since the typical bead deformations are in the order of a nanometer, these sensors essentially have no moving parts. This photonic sensor concept can be extended to a system of distributed sensors providing spatial data resolved in time and space. The talk will provide an overview of WGM optical phenomenon and present several WGM-based sensors developed in SMU’s Micro-Sensor Laboratory. Specifically, the performance of prototype sensors for electric field, wall shear stress and wall pressure will be discussed. Click here to view the annoucement.
Professor Otugen received his BS degree in Naval Architecture and Marine Engineering from Istanbul Technical University in 1978. He received the MS and Ph.D. degrees in Mechanical Engineering and Mechanics from Drexel University in 1982 and 1986, respectively. He worked as a Research Analyst in the Mechanical and Aerospace Engineering Department at Arizona State University between 1986 and 1988. He joined the faculty of Aerospace Engineering at Polytechnic University in 1988. He served on the faculty of Polytechnic University until he joined SMU in 2007 as the chair of the Mechanical Engineering Department. Currently, he is the Senior Associate Dean of Engineering at SMU. He also holds the George R. Brown Endowed chair position Mechanical Engineering and is the director of the Micro-Sensor Laboratory at SMU. Dr. Otugen’s expertise is in experimental and theoretical fluid mechanics, optical measurement techniques, plasma aerodynamics and micro-optical sensor technology. His research has been funded by federal agencies as well as private sources including, NSF, NASA, DoD, DoE, GRI and Northrop-Grumman. He has lectured extensively on turbulent fluid mechanics, measurement techniques and micro-sensor technology, nationally and internationally and he is the author or coauthor of over 130 articles. He has received the SAE Ralph Teetor Award for Excellence in Education in 1993 and is a Fulbright Fellow (1998). He is a fellow of ASME and an associate fellow of AIAA.