Characterization of 1/spl times/N broadcast and 2/spl times/N multicast packet switching using active-vertical-coupler-based optical crosspoint switch

This paper reports the expansion of a novel optical multicast scheme to 1-to-4 and 2-to-4 configurations using an active-vertical-coupler (AVC)-based optical crosspoint switch (OXS) matrix. A 1-to-4 broadcast experiment has been carried out first, with only 0.5 dB excess loss per signal split. Input signals with two wavelengths are then fed into one row of OXS to investigate the effect of wavelength-division multiplexing on the 1-to-4 multicast switching. Finally, combining both, the expanded 2-to-N multicast is also achieved with an N value up to 4. The switching characteristics, switched signal quality, and optical signal-to-noise ratio (OSNR) have been investigated in different configurations. Power penalties of less than 4.5 dB are found in worst case switched signals in the 2-to-4 configuration. Slow OSNR degradation in line with previous prediction is also observed. The measured results confirm the excellent multicast switching characteristics nearly free from power splitting loss in this device