The Department of Physics and Astronomy invites all to a colloquium featuring Dr. Silvano Donati, Emeritus of University of Pavia, IEEE Life Fellow, OSA Emeritus Fellow, SPIE Life Member. Dr. Donati will present his talk, “From Order to Chaos and back: a High-Level Coupling Approach for Cryptography of Transmitted Data”, Tuesday, Sept. 13, at 4:10 p.m. in Webster 17.
Meet for refreshments before the lecture at 3:45 – 4:10 p.m. in the foyer on floor G above the lecture hall.
Abstract: In this talk, we start with a theoretical introduction to mutual- and self-coupling in laser oscillator, and then describe the application to optical chaos and cryptography. Chaos is generated by the laser source at strong level of coupling, in the mutual or self-injection regime. The mutual regime displays a rich dynamics of multi-periodicity and chaos found between the first and the final locking, and the associated time, frequency and state diagrams. We point out that, by injecting the chaos-generated signal into a slave system, we can drive the latter to the same chaos, or, be able to synchronize it. Synchronization is the crucial issue leading to cryptography of the message, and two possible schemes are then developed: ACM (additive Chaotic Masking) and CSK (Chaos Shift Keying). Of these schemes, we discuss the block diagram and the performance parameters. We then look for the most viable and robust configuration to implement cryptography, and develop chaos generators based a self-injected semiconductor laser. We show how to adapt the mutual-injected concept of chaos generation to this case, and how they may be regarded as equivalent. Last, we describe the experimental development of chaos-based transmission, reporting on in-field trial experience. (Updated version from: the LEOS Distinguished Lecturer Program) paper on Progress in Quantum Electronics, 2012
