Optical quantizing and coding for ultrafast A/D conversion using nonlinear fiber-optic switches based on Sagnac interferometer.

Abstract

We propose a novel optical quantizing and coding for ultrafast analog-to-digital (A/D) conversion using nonlinear optical switches based on Sagnac interferometer. The feasibility of a 3-bit A/D conversion at 10-Giga-sample-per-second (Gsps) is experimentally demonstrated. Multi-period transfer function of the Sagnac interferometer type nonlinear fiber-optic switch, which is a key to the quantizing and coding, is experimentally realized for the first time to the authors' knowledge. The proposed optical quantizing and coding, combined with existing optical sampling techniques, will enable ultrafast photonic A/D conversion without high-speed electronics, potentially in the frequency region of well over a few hundred Gsps.