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All-Optical Sigma-Delta Modulator For Analog-To-Digital Conversion, Bin Zhang

Graduate Theses - Physics and Optical Engineering

In this thesis, an all-optical sigma-delta (ΣΔ) modulator for analog-to-digital conversion (ADC) using a novel optical bistable switch, the SOA-PD device, is demonstrated. The presented all-optical ΣΔ modulator consists of a photonic leaky integrator, the SOA-PD optical comparator, and a positive feedback loop. The switching properties of the SOA-PD device are studied and experimentally tested to confirm its performance. Then the all-optical ΣΔ modulator is designed according to the switching performance of the SOA-PD device. It is demonstrated that the all-optical ΣΔ modulator is capable of producing an inverted non-return-to-zero (NRZ) type binary output for frequencies in the range of …