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We propose and experimentally demonstrate a segmented waveguide taper (SWT) mode adapter for a polarization mode converter to reduce excess loss induced by a 100-\mum-wide waveguide gap housing a 92-\mum-thick quartz half waveplate. The SWT mode adapter is a combination of periodically segmented waveguide taper and traditional taper formed in a silica-based waveguide. It is proved that this SWT mode adapter requires no vertical tapering process but can enlarge the mode size in both vertical and horizontal directions. Our newly designed SWT mode adapter based on the 0.75%-\Delta silica waveguide is able to reduce the excess loss significantly from 5 dB to less than 1.5 dB. [ABSTRACT FROM PUBLISHER]

We study the fundamental lower bound for node buffer size in intermittently connected wireless networks. The intermittent connectivity is caused by the possibility of node inactivity due to some external constraints. We find even with infinite channel capacity and node processing speed, buffer occupation in each node does not approach zero in a static random network where each node keeps a constant message generation rate. Given the condition that each node has the same probability (p) of being inactive during each time slot, there exists a critical value (p_c(\lambda )) for this probability from a percolation-based perspective. When (pp_c(\lambda )), the network is in the subcritical case, and there is a tight lower bound (\Theta (\sqrtn)) for buffer occupation, where $(n)$ is the number of nodes in the network. [ABSTRACT FROM PUBLISHER]