125-µm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects. - Tetsuya Hayashi; Tetsuya Nakanishi; Kaoru Hirashima; Osamu Shimakawa; Fumiaki Sato; Koichi Koyama; Akira Furuya; Yasunori Murakami; Takashi Sasaki (OFC, 2015)