A high-speed learning method for analog neural networks. - Takao Matsumoto; Masafumi Koga (IJCNN, 1990)

Proposal for neural-network applications to fiber-optic transmission. - Takao Matsumoto; Masafumi Koga; Kazuhiro Noguchi; Shigeki Aizawa (IJCNN, 1990)

Large-capacity optical path cross-connect system for WDM photonic transport network. - Masafumi Koga; Atsushi Watanabe; Takeshi Kawai; Ken-ichi Sato; Yasuji Ohmori (IEEE J. Sel. Areas Commun., 1998)

Robust photonic transport network implementation with optical cross-connect systems. - Satoru Okamoto; Masafumi Koga; Hiro Suzuki; Kenji Kawai (IEEE Commun. Mag., 2000)

GMPLS-based photonic multilayer router (Hikari router) architecture: an overview of traffic engineering and signaling technology. - Ken-ichi Sato; Naoaki Yamanaka; Yoshihiro Takigawa; Masafumi Koga; Satoru Okamoto; Kohei Shiomoto; Eiji Oki; Wataru Imajuku (IEEE Commun. Mag., 2002)

Advances in optical path crossconnect systems using planar-lightwave circuit-switching technologies. - Shigeki Aisawa; Atsushi Watanabe; Takashi Goh; Yoshihiro Takigawa; Masafumi Koga; Hiroshi Takahashi (IEEE Commun. Mag., 2003)

Foreword. - Masafumi Koga (IEICE Trans. Commun., 2011)

Photonic network vision 2020 - Smart photonic networking, synthetic transport platform, and scale-free photonics. - Ken-ichi Kitayama; Masaki Fukui; Naoaki Yamanaka; Masahiko Jinno; Atsushi Hiramatsu; Takehiro Tsuritani; Satoru Okamoto; Masafumi Koga (GLOBECOM Workshops, 2013)

Simply configured Radio on Fiber link yielding positive gain for mobile phone system. - Junji Higashiyama; Yoshiaki Tarusawa; Masafumi Koga (IEICE Electron. Express, 2014)

Nonlinear phase-shift cancellation by maximum-ratio combining WDM phase-conjugate diversity lights transmitted through multi-core fiber. - Masafumi Koga; Mitsuki Moroi; H. Takara (ECOC, 2015)

Optical diversity transmission with signal and its phase-conjugate lights through multi-core fiber. - Masafumi Koga; Akira Mizutori; Teppei Ohata; H. Takara (OFC, 2015)

Frequency nondegenerate optical parametric phase-sensitive amplifier repeater by using recovered pump carrier generated from phase-conjugated twin waves. - Yasuhiro Okamura; Kotaro Kondo; Shingo Seki; Yuya Ohmichi; Masafumi Koga; Atsushi Takada (OFC, 2016)

Optical 16-QAM signal homodyne detection by extracting +/-π/4 and +/-3π/4-phase symbols. - Akira Mizutori; T. Abe; Takahisa Kodama; Masafumi Koga (OFC, 2017)

Nonlinear Phase-Shift Cancellation by Taking the Geometric Mean of WDM-Signal Phase-Conjugate Pair. - Takahisa Kodama; Akira Mizutori; Takayuki Kobayashi; Takayuki Mizuno; Masafumi Koga (IEICE Trans. Commun., 2018)