Impact of cumulative polarization-dependent gain on SOA-based optical packet switching networks

The physical layer scalability of multistage interconnection networks is determined by the maximum number of internal switching nodes that packets can traverse error-free. We show that for nodes based on commercial semiconductor optical amplifier switches with polarization-dependent gain of less than 0.35 dB, the maximum number of cascaded nodes could vary by as much as 20 nodes, depending both on the packet wavelength and its state of polarization. We explain such a dramatic effect by optical signal-to-noise ratio degradation due to accumulated amplified spontaneous emission noise with the number of nodes.     

Bit-parallel message exchange and data recovery in optical packet switched interconnection networks

Multiwavelength optical messages encoded in a bit-parallel fashion are successfully routed through five switching nodes of a 12-port optical packet switching interconnection network. The data payloads are entirely recovered and processed at the destination node using an embedded clock signal with a measured clock-to-data skew tolerance window of 150 ps.     

Polarization-Dependent Gain in SOA-Based Optical Multistage Interconnection Networks

The small polarization dependence (< 1 dB) of optical components becomes significant in optical multistage interconnection networks. The cumulative effect can ultimately limit physical layer scalability by changing the maximum number of internal nodes that optical packets can traverse error free. It is shown that for nodes based on commercial semiconductor optical amplifier (SOA) switches with polarization-dependent gains of less than 0.35 dB, the maximum number of cascaded nodes changes by as much as 20 nodes, depending on both the packet wavelength and its state of polarization. This deviation in the number of nodes could correspond to a 100-fold decrease in the number of interconnected ports of an optical interconnection network such as the data vortex. This dramatic effect is explained in terms of optical signal-to-noise ratio degradation due to accumulated amplified spontaneous emission noise originating from the SOA device in the node     

A fully implemented 12 /spl times/ 12 data vortex optical packet switching interconnection network

A fully functional optical packet switching (OPS) interconnection network based on the data vortex architecture is presented. The photonic switching fabric uniquely capitalizes on the enormous bandwidth advantage of wavelength division multiplexing (WDM) wavelength parallelism while delivering minimal packet transit latency. Utilizing semiconductor optical amplifier (SOA)-based switching nodes and conventional fiber-optic technology, the 12-port system exhibits a capacity of nearly 1 Tb/s. Optical packets containing an eight-wavelength WDM payload with 10 Gb/s per wavelength are routed successfully to all 12 ports while maintaining a bit error rate (BER) of 10/sup -12/ or better. Median port-to-port latencies of 110 ns are achieved with a distributed deflection routing network that resolves packet contention on-the-fly without the use of optical buffers and maintains the entire payload path in the optical domain.