Boston Chapter of the IEEE Photonics Society

Abstract:  The key material used in manufacturing electronic chips, Silicon (Si), is not a good photonic material since it is a poor light emitter with negligible electro-optic effect.  For this reason, the expensive technology of III-V compound semiconductors (like GaAs or InP, with superior optical performances) have been almost exclusively used in the business of optoelectronic devices.  However, if photonics is ever to find its way onto a disruptive low cost technology, silicon-compatible (CMOS-compatible) approaches of integrating electrical and optical functionalities on Si chip need to be investigated.  

In this talk I will give a panoramic overview of my research activity on Silicon Photonics.  The research is aimed to engineer potential new solutions for CMOS-compatible light emission and light control in silicon-based systems of reduced dimensionality, where both quantum confinement and surface chemistry effects start to play a crucial role in the optical properties of the materials.  I will review the main results obtained along two closely related research directions: the use of nano-sized silicon to achieve efficient light emission and optical amplification and the possibility to control and manipulate light states in silicon-based photonic structures.  In particular, I will introduce the potential of Silicon nanocrystals (Si-nc) embedded in SiOx and SiNx dielectric matrices for efficient light emission, electrical injection and energy coupling (sensitization) with rare earth ions, specifically Erbium3+ ions emitting at 1.55mm.  In addition, I will show how light emission can be enhanced by embedding Si-nanostructures into aperiodic photonic structures with significant field-enhancement effects and strong light-matter coupling.  Finally, I will discuss our recent work on aperiodic metal/dielectric nanostructures and plasmonics slot waveguides as an emerging template for field transport with deep-subwavelength confinement.

Biography:  Luca Dal Negro received both the Laurea in physics, summa cum laude, in 1999 and the Ph.D. degree in semiconductor physics from the University of Trento, Italy, in 2003.  After his Ph.D., in 2003 he joined MIT as a post doctoral associate.  Since January 2006 he is Assistant Professor in the Department of Electrical and Computer Engineering at Boston University.

He manages and conducts research projects on silicon-based photonic materials and devices and semiconductor laser spectroscopy.  His main focus is currently on quantum dots spectroscopy, complex photonic crystals structures and nano-photonics.  He has authored and coauthored more than 50 technical articles.

Location:  Verizon Laboratories