Micro/nano-scale optical circuits and networks: issues, challenges and progresses

We present a comprehensive overview of our original work on the theory, design, fabrication, and integration of micro/nano-scale optical circuits and networks (O-MNN). This is an extension of the macro-scale optical networks and electrical networks down to the level of micro/nano-scale. It also intends to compliment the limitations of the electrical circuits and networks by way of processing optical signals through micro/nano-optical networks while the electrical systems process electrical signals through the electrical networks. The micro/nano-optical circuits perform the functions of sensing, storing, transporting, processing, switching, routing, and distributing optical signals on flat modular boards or chips. The integrated optical components include micro/nano-scale light sources, waveguides, detectors, switches, modulators, sensors, directional couplers, multi-mode interference devices, AWGs, ring-resonators, photonic crystal devices, plasmonic devices, and quantum devices, made of polymer, silicon and other semiconductor materials. Some molecular devices are also considered. The paper discusses scientific and technological issues and approaches concerning the miniaturization, interconnection and integration of micro/nano-scale photonic devices, circuits, and networks leading to ultra-small and very large scale integration as applicable for datacom, telecom, transportation, aero/space/avionic and bio/sensor/environmental systems. Scaling rules for the miniaturization and integration of the micro/nano-photonic systems will be discussed in comparison with those of the electronic systems. New physics, visions and challenges of the optical micro/nano-optical networks and systems will be discussed along with the historical perspectives of the electrical technology. Progresses and examples are presented.