5 mW/Gbps hybrid-integrated Si-photonics-based optical I/O cores and their 25-Gbps/ch error-free operation with over 300-m MMF. - Kenichiro Yashiki; Yasuyuki Suzuki; Yasuhiko Hagihara; Mitsuru Kurihara; Masatoshi Tokushima; Junichi Fujikata; Akio Ukita; Koichi Takemura; Takanori Shimizu; Daisuke Okamoto; Jun Ushida; Shigeki Takahashi; et al. (OFC, 2015)