**Acknowledgements**

The author thanks Drs. K. Shiraki and T. Kurashima at NTT Access Service Systems Laboratories (ANSL) for their encouragement and helpful suggestions. The author is deeply grateful to R. Koyama, K. Saito, Y. Yamaguchi, and Y. Machida at ANSL for discussing the low insertion APC-MPO connectors and high-density MT connectors; T. Shimizu and C. Fukai at ANSL for discussing the novel optical switch based on MT connector technology; K. Noda and K. Nakashoji for helpful discussions regarding the inspection technique for MT ferrules; and Dr. T Satake at USConec Ltd. for providing the pictures of **Figure 2**.
