Influence of Transmission Impairments on the OSMOSIS HPC Optical Interconnect Architecture

We examine the impact of transmission impairments on the performance of the optical supercomputer interconnect architecture, initially proposed in the context of the optical shared memory supercomputer interconnect system (OSMOSIS) project. We study two versions of the aforementioned optical interconnect that differ in terms of the number of semiconductor optical amplifiers (SOAs) used as ON-OFF gates. For practical reasons related to packet arbitration, the size of the crossbar switch of the optical interconnect in this study is limited to 64 ports. The switch is based on a broadcast-and-select architecture and employs DWDM in conjunction with 10 Gb/s intensity modulation/direct detection per wavelength channel. We show, both by experiment and by simulation, that the minimization of the number of SOAs in the optical switch by taking advantage of the cyclic routing capability of optical arrayed waveguide multiplexers/demultiplexers leads to negligible performance deterioration compared to conventional wavelength-space switches that are prohibitive slower and do not use any inherent gain properties like in OSMOSIS.