Pillsbury Winthrop LLP
Optical waveguide circuit, its manufacturing method and optical waveguide module having the optical waveguide circuit
 In a light waveguide circuit including a plurality of waveguides having different length, a material (10) having a temperature coefficient of a refractive index including a symbol different from that of a temperature coefficient of an effective refractive index of the waveguide (4) is charged into a groove (12) formed by removing the upper clad and the core from the waveguide (4), or a groove (12) formed by removing the upper clad, the core and the lower clad from the waveguide (4). A difference in length of the removed portions between adjacent waveguides is proportional to a difference in length of the waveguides which were not removed and remained. 
Nippon Telegraph and Telephone Corporation NTT Electronics Corporation
G G G G
G02B G02B G02B G02B
inventional inventional inventional inventional
Kuninori Motohiro Fumiaki Motohaya Yasuyuki Akimasa Fumihiro Senichi Hiroshi Katsunari Kenji Takashi Shin Koichi Hiroaki
Hattori Nakahara Hanawa Ishii Inoue Kaneko Ebisawa Suzuki Takahashi Okamoto Yokoyama Yoshida Sumida Arishima Yamada