Compact and Low-Loss ZrO2-SiO2 PLC-Based 8 × 8 Multicast Switch for CDC-ROADM Application

In this paper, we report design and characteristics of a compact and low-loss multicast switch (MCS) based on a high Δ planar lightwave circuit (PLC) which consists of ZrO2 doped silica glass. Chip size of an 8 × 8 MCS consists of an eight-arrayed 1 × 8 splitter and an eight-arrayed 8 × 1 switch is reduced to 30 mm × 9 mm by using the ZrO2-SiO2 PLC with 5.5%-Δ. Eight-input and eight-output ports of the MCS are arrayed at the one side of the chip, and coupled to optical fibers with a 16-fiber V-groove array. A high Δ fiber is used to reduce coupling loss to the ZrO2-SiO2 PLC, and the high Δ fiber is spliced to a single-mode fiber (SMF) by using low-loss splicing technique. Coupling loss between the ZrO2-SiO2 PLC and the SMF is reduced to 0.4 dB/facet. Average insertion loss of the fabricated MCS is 12.8 dB including coupling loss to the SMF. Extinction ratio and polarization dependent loss of the MCS are over 50 dB and less than 0.5 dB in L-band, respectively.