All-optical Multi-wavelength Virtual Memory Architecture - Design and Performances Analysis

As all-optical memory represents one of the most important lacks in evolution of optical networks; this paper presents an all-optical virtual memory based on a recirculation loop, with the goal of providing optical data unit storage in all-optical switching networks. The concept of multi-wavelength signal buffering is adopted, to realize a shared buffer with an important storage capacity. We propose the organization of the buffer in two loops, the first as a delay loop and the second as an amplification loop, to improve the buffering duration and performances. The memory implementation is demonstrated using optical components such as fiber Bragg gratings (FBG), circulator and tunable wavelength converter. An all-optical control unit is designed to provide a dynamic and automatic signal buffer managing. An analytical model is implemented and a simulations set is done to prove that the proposed architecture is able to confine several signals for a relatively long time as a memory and signals can leave the architecture for a reasonably short delay after the departure decision is taken. The low penalty observed shows good system reliability.