LiTPiC -- Light-trails and Photonic Integrated Circuits: Issues of Network Design and Performance

A recent advance in high-speed networks is the concept of Photonic Integrated Circuits (PICs) on an Indium Phosphide substrate, allowing miniaturization and integration of multiple OE and EO modules in a chip. PICs have the potential to do away with the opto-electronic bandwidth mismatch as well as result in severe cost reduction, hence questioning the need for all-optical networking. In this paper we analyze the impact of this digital optical networking concept by combining PIC technology with an all-optical solution - light-trails, resulting in a new solution called LiTPiC (Light-Trail Photonic Integrated Circuit). LiTPiCs offer the best of both digital and all-optical worlds. By enabling selective (and on-demand) regeneration of the signal, we are able to enhance the reach of all-optical light-trails. In addition, we are able to partition light-trail buses into multiple geographically disjoint sub-buses called PIC-Trails, thus for the first time introducing wavelength reuse within a light-trail. The LiTPiC concept gives PICs a new direction - that of being a technology enabler for next generation services using ROADM (Reconfigurable Optical Add-Drop Multiplexer) architecture and a complementary solution to the light-trail technology.