Yutaka SHIBATA^*, Takanori SUZUKI and Hiroyuki TSUDA

School of Integrated Design Engineering, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan

(Received January 14, 2004; Accepted February 27, 2004)

We proposed and fabricated an N:N optical coupler using an integrated waveguide mirror. Optical circuits can be miniaturized with small bending by reflecting mirrors. The parabolic curve was applied to the mirror shape because it was necessary to collimate the reflected beam so as to distribute the input light to the output waveguides. We fabricated the 8:8 optical coupler using silica waveguide. The chip size was about 7 mm× 15 mm. The excess loss of the device was about 8 dB larger than simulation results calculated using beam propagation method. The dependence on the wavelength and polarization was about 0.4 and 0.15 dB, respectively. The excess loss was mainly attributed to the mirror tilt and will be reduced by optimizing the etching conditions to decrease the mirror tilt angle.

Key words: optical waveguide, mirror, collimating beam, optical coupler, reflection, silica waveguide

^*E-mail address: s-yutaka@tsud.elec.keio.ac.jp