Patent ID: 6049643
Filing Date: 2000-04-11
Classification: G02B

Abstract:
A modal evolution optical coupler comprising:a first optical fiber which gradually, thermally expands a core to evolute the mode of a transmitted light;a second optical fiber which gradually, thermally expands a core to evolute the mode of a transmitted light;an expanding element which is disposed between said first and second optical fibers, and which is formed of an ultraviolet curing resin, and which has ends whose section areas are equal to the respective ends of said first and second expanded optical fibers when an ultraviolet ray is incident thereon and cured, and which includes expanded portions which are each expanded over a predetermined expansion distance starting from a connecting portion to said first or second optical fiber and a middle portion keeping its size constant for a predetermined length between said expanded portions of said first and second optical fibers, and does not move in said expansion distance;a channel transmission path which has two ends to which said first and second optical fibers are respectively connected and allows said transmitted light to be output after said expanding element is disposed between said optical fibers placed on said two ends thereof; anda coverlet positioned on said channel transmission path to enable a filling of said channel transmission path with an ultraviolet curing resin while aligning said first and second optical fibers and to prevent said resin from flowing out of said channel transmission path.