A Polarization-Independent Subnanosecond 2 2 Multicast-Capable Optical Switch Using a Sagnac Interferometer

Abstract—We design and demonstrate a cost-effective 2 2 ultrafast multicast-capable optical switch (MCOS) based on a Sagnac interferometer. The Sagnac interfer-ometer is composed of a LiNbO phase modulator (PM) with two polarization-maintaining pigtail fibers and a 3-dB polarization-maintaining coupler. The MCOS works at three states: cross, bar, and multicast, in the entire -band (1525–1565 nm) by controlling the driven voltage of the PM. Polarization- dependence is eliminated by splicing the pigtail fibers of the PM and the 3-dB coupler with 0 and 90 angles, respectively. The measured switching time is 0.6 ns. Multiple 2 2 MCOS elements can be constructed into a large nonblocking MCOS matrix. Index Terms—Multicast, optical packet switch, phase modulator (PM), polarization-independent, Sagnac interferometer, ultrafast. I