The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 2001
Filed:
Oct. 14, 1998
Yasuyuki Inoue, Mito, JP;
Akimasa Kaneko, Mito, JP;
Hiroshi Takahashi, Mito, JP;
Fumiaki Hanawa, Hirachiota, JP;
Kuninori Hattori, Yokosuka, JP;
Kenji Yokoyama, Tsuchiura, JP;
Senichi Suzuki, Mito, JP;
Shin Sumida, Tsukuba, JP;
Katsunari Okamoto, Mito, JP;
Motohaya Ishii, Mito, JP;
Hiroaki Yamada, Hitachinaka, JP;
Takashi Yoshida, Mito, JP;
Koichi Arishima, Mito, JP;
Fumihiro Ebisawa, Ibaraki-ken, JP;
Motohiro Nakahara, Mito, JP;
Other;
Abstract
In a light waveguide circuit including a plurality of waveguides having different length, a material (,) 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 (,) is charged into a groove (,) formed by removing the upper clad and the core from the waveguide (,), or a groove (,) formed by removing the upper clad, the core and the lower clad from the waveguide (,). 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.