Photonic ATM switch using vertical-to-surface transmission electro-photonic devices (VSTEPs)

Abstract

This paper proposes a new architecture of photonic ATM switch for the purpose of eventually moving beyond the terabits-per-second (Tbps) level throughout ATM operation. The proposed architecture is based on vertical-to-surface transmission electro-photonic devices (VSTEPs) which can be used both as an optical buffer memory and as an optical self-routing circuit. Since VSTEP is an integrated two-dimensional array, the VSTEP-based optical buffer memory using massively parallel optical interconnections based on the free-space optical beam propagation is an effective solution to achieve ultrahigh throughput in the buffer. The optical cell signal speed in the proposed optical buffer memory can reach about 10 Gbps. By using the VSTEP function as the optical header-driven gates in a two-dimensional array, the high-speed and large-capacity optical self-routing circuit can be fabricated without being limited by the electric control circuit operation. In the proposed optical self-routing circuit, priority control to prevent collision among cell signals at the output port in the case of cell signal contention can easily be achieved. The numbers of possible input and output ports in the self-routing circuit are estimated to be around 100. An optical header is inserted at the front of the ATM cell signal for processing at the self-routing circuit. To reduce the overhead of the optical header, a wavelength-division technique also is proposed for the self-routing circuit. Finally, experiments on operations of both the buffer memory and the self-routing circuit with priority control for 1.6-Gbps optical cells are carried out successfully.