ECE Seminar with Dr. Michele Ortolani

2:00 pm on Friday, February 8, 2013
Photonics Center, 8 Saint Mary’s St., Room 339
Mid-Infrared Surface Plasmon Polariton Sensors Based on Subwavelength Hole Arrays and Quantum Cascade Lasers With Dr. Michele Ortolani Sapienza University of Rome, Italy Faculty Host: Hatice Altug Refreshments will be served outside Room 339 at 1:45 p.m. Abstract: Dr. Michele Ortolani will present an experimental study of subwavelength hole arrays in thin metal films employed as surface-enhanced optical sensors operating in the mid-infrared. An analytical model of the Fano interference between resonant surface plasmon polaritons and the sub-diffraction-limit Bethe continuum is developed to fit the experimental transmission spectra in the 2-10 micron wavelength range. The absolute polariton frequency shifts after deposition of dielectric layers (2.6 to 24 nm thickness) are extracted from the differential transmission spectra and their values are related to the numerically calculated electric field profiles. Sensor operation is demonstrated by determining, from a single FT-IR measurement, both the thickness and the absorption spectrum of phospholipid layers, obtained by liposome adsorption. Finally, he will demonstrate that the use of a collimated beam emitted by a Quantum Cascade Laser provides an enhancement of the thickness sensitivity of our sensors by one order of magnitude at least. About the Speaker: Dr. Michele Ortolani is a Research Associate at Sapienza University of Rome, Italy. He holds a Ph.D. in materials science (2004), and he performed infrared and terahertz spectroscopy of novel materials for optics and electronics. He is currently working on the development of mid-infrared and terahertz semiconductor devices in the framework of a Young Investigator Grant of the Italian Ministry of Research. He is a member of the program committee of the IEEE Conference on Infrared, Millimeter and Terahertz Waves.