Loss reduction of silica-based 8 × 8 optical matrix switch by optimizing waveguide crossings using WFM method. - Yohei Sakamaki; Shunichi Sohma; Takashi Saida; Toshikazu Hashimoto; Hiroshi Takahashi; Tomohiro Shibata (IEICE Electron. Express, 2007)

Wide passband tandem MZI-synchronized AWG employing mode converter and multimode waveguide. - Manabu Oguma; Shin Kamei; Tsutomu Kitoh; Toshihiko Hashimoto; Yohei Sakamaki; Mikitaka Itoh; Hiroshi Takahashi (IEICE Electron. Express, 2010)

Reduction of phase-difference deviation in 90° optical hybrid over wide wavelength range. - Yohei Sakamaki; Yusuke Nasu; Toshikazu Hashimoto; Kuninori Hattori; Takashi Saida; Hiroshi Takahashi (IEICE Electron. Express, 2010)

Compact and Athermal DQPSK Demodulator with Silica-Based Planar Lightwave Circuit. - Yusuke Nasu; Yohei Sakamaki; Kuninori Hattori; Shin Kamei; Toshikazu Hashimoto; Takashi Saida; Hiroshi Takahashi; Yasuyuki Inoue (IEICE Trans. Electron., 2010)