An optical quantizing and coding method for all-optical ADC based on asymmetrical nonlinear optical-loop mirrors

Abstract

Self-and cross-phase modulation (SPM, XPM) in fiber is expected to play a major role in ultrafast all-optical analog-todigital conversion(ADC), which can overcome the obstacles of inherently limited operating speed of electronic ADC. In this paper, we propose an optical quantizing and coding method for all-optical ADC based on asymmetrical nonlinear optical-loop mirrors . The multiperiod transfer function, which is the key to quantizing and coding, is achieved through a careful design of the asymmetrical nonlinear optical-loop mirrors. We conducted proof-of-principle numerical simulation and successfully demonstrated 3-bits all optical ADC with Gray code output, it is ready for experiments in future. The proposed optical quantizing and coding, combined with existing optical sampling techniques, will enable ultrafast photonic ADC without electronics.