New architectures for optical packet switching using QD-SOAs for multi-wavelength buffering

We present two architectures for implementing optical buffers. Both use multi-wavelength selective elements like quantum dot semiconductor optical amplifiers (QD-SOAs) as multi-wavelength converters and fixed-length delay lines that are combined to form both an output queuing and a parallel buffer switch design. The output queuing buffer design requires less active devices (QD-SOA) when implementing large buffers, but the parallel buffer design becomes more profitable, when the number of wavelength channels that can be simultaneously processed by the wavelength selective switches (QD-SOAs) increases. This is because the number of active devices depends only on the buffer size. We also proposed scheduling algorithm to resolve packet contention in parallel buffer architecture and carried out a simulation considering mean packet delay, maximum buffer occupancy and packet loss probability.