Optotronics: Optically Inspired Electronics

Citation

Afshari, Ehsan (2007) Optotronics: Optically Inspired Electronics. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z95M63XK. https://resolver.caltech.edu/CaltechETD:etd-08042006-144107

Abstract

Waves are everywhere, from the distribution of cars on a highway to the wave patterns in the ocean. Intriguing phenomena in wave propagation, such as Soliton resonance, kink-antikink interaction, self-focusing, and Peakon generation can be used in many practical applications leading to novel architectures for signal processing and generation. These E/M based approaches could be particularly useful in the case of Extremely Wide Band (EWB) (DC to more than 100GHz) circuits and systems where the limited transistor cut-off frequency, maximum power efficiency, and breakdown voltage pose serious constraints on the use of conventional circuit techniques.

To overcome the limitations of active devices in EWB signal processing and generation, we propose a general class of solutions based on novel circuit topologies inspired by commonly used structures in electromagnetics, and more specifically optics. The proposed methodology is based on nonlinear and/or inhomogeneous one-dimensional (1D) transmission lines which we have successfully extended to two-dimensional transmission lattices. The principles behind these designs stem from the mathematical theory of linear and nonlinear wave propagation. By analyzing the models for the transmission lines/lattices, we are able to exploit the large body of theory to design circuits, demonstrating the narrowest reported pulse on silicon (2.5ps), and for a single integrated-circuit silicon-based amplifier, the highest achieved center frequency of operation (85GHz) and the highest achieved power output (120mW) at this frequency. In addition, we have reported the first in-silicon transmission line system capable of sharpening both rising and falling edges of NRZ data by increasing the bandwidth. In the end, we will also present how the same approach can be applied to realize ultra-fast computation systems (such as a sub-nanosecond Fourier and Hankel transformers in silicon) and other structures, leading to a new design discipline we like to call "Optotronics".

Thesis Files