Ali Elshaari


Quantum-based communication systems can potentially achieve the ultimate security from eavesdropping and greatly reduce the operating powers on chip. Light-speed transmission, noise immunity, and low noise properties make photons indispensable for quantum communication to transfer a quantum state through a transmission line. Furthermore, the field of silicon nanophotonics is fast growing field which is driven by the attractive and promising improvements it has to offer in high speed communication systems and on chip optical interconnects. Consequently, there is a high demand to develop the building blocks for photon manipulation in silicon nanophotonic circuits. The goal of the work is to enable high performance optoelectronic computing and communication systems that overcome the barriers of electronics and dramatically enhance the performance of circuits and systems. We will focus our attention on solving some of the issues with the current systems regarding photon storage, routing, isolation, switching, and energy conversion. We realize a continuously tunable optical memory which breaks the time-bandwidth limit by more than thirty times. This enabled the storage of ultra-short pulses of light for hundreds of picoseconds. Also, we investigate on-chip photon scattering when transmitted through micro-scale optical cavities. In addition, we develop novel dynamic quantum mechanical models that predict quantum-like behavior of single and multi-photon wavepackets. Furthermore, we report for the first time that efficient red shifts in silicon are achievable with free carrier injection which generally produces blue wavelength shifts. We realize adiabatic wavelength conversion and discrete photonic transitions of single photons in silicon cavities. Moreover, we demonstrate a basic quantum network on chip with an on-chip photon source. We present a novel design for CMOS compatible optical isolator on silicon chip using a system of active cavities. And finally, we analyze a novel ultra-fast broadband modulator in silicon based on free-carrier absorption effect in SOI waveguides integrated with Schottky diodes.

Library of Congress Subject Headings

Quantum communication; Nanophotonics; Nanosilicon

Publication Date


Document Type


Student Type


Degree Name

Microsystems Engineering (Ph.D.)

Department, Program, or Center

Microsystems Engineering (KGCOE)


Preble, Stefan


Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: QA76.889 .E57 2011


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