Smart Materials and Systems Seminar Series
Department of Mechanical Engineering
Southern Methodist University
The term “whispering gallery mode” has been used in recent years to refer to the optical modes of dielectric resonators. The whispering gallery mode (WGM) phenomenon was first observed by Lord Rayleigh inside the dome of St Paul Cathedral in London while studying the propagation of sound over curved gallery surface (A whisper can be heard by someone standing against the opposite wall, but not by someone standing at the center of the room).
This talk describes the development of micro-photonic devices based on the same fundamental concept of acoustic resonances. More precisely, the concept is based on the optical mode (WGM) shifts of dielectric resonators. One of the inherent optical qualities of such devices is the high quality factors they exhibit. The quality factor is a measure of how well an optical resonance (or WGM) is resolved. The very high quality factor (typically107) allows for the determination of very small morphology-dependent shifts in WGMs of optical resonators and raises the possibility of development of new micro-photonic devices. The morphological changes (such as size, shape or the optical constants) of the resonator can be caused, for example, by a change in the physical condition of the surrounding. Therefore, by monitoring the WGM shifts, one may determine the change in a physical condition of the environment in which the resonator is embedded.
Dr. Tindaro Ioppolo received his Laurea Degree in Aeronautical Engineering from the University of Palermo (Italy) and his PhD in mechanical engineering from the Polytechnic University in 2008. During his PhD he investigated the interaction of acoustic waves with DC glow discharge plasma, to assess the possibility of using the discharge as a sound barrier for aeroacoustic noise management and flow control. After the conclusion of this study, he started a new project that involved research for the development of novel micro-photonic sensors based on whispering gallery modes (WGM) of dielectric
resonators. After receiving his PhD, he joined the Department of Mechanical Engineering at Southern Methodist University as post-doctoral fellow. On September 2010 he became a research assistant professor in the same department where he is responsible for the day-to-day operation of the Micro-Sensor Laboratory. Currently he is working on a project funded by the Defense Advanced Research Project Agency (DARPA) for the development of a novel photonic interface to neural activity that will support both in vitro and in vivo applications. Dr. Ioppolo has 2 pending U.S. patents, and is a member of the American Institute of Aeronautics and Astronautics (AIAA), American Physics Society (APS) and member of society of Photo-Optical Instrumentation Engineers (SPIE).