Date of Award

Summer 7-2013

Document Type


Degree Name

Master of Science in Optical Engineering


Department of Physics and Optical Engineering

First Advisor

Dr. Azad Siahmakoun

Second Advisor

Dr. Bruce Black


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 dozens of kilohertz. The limit cycle frequency of the ADC system is about 250 kHz, which is limited by the maximum switching speed of the SOA-PD device. Through noise analysis of the system, SNR and ENOB of the system are calculated to be 25.3 dB and 3.93 bits respectively.