Apparatus and method for fabricating optical fiber coupler

A method for fabricating an optical fiber coupler comprising:

• preparing an optical fiber strand having at least two segments of optical fibers, and a quartz tube having a length smaller than that of said fiber strand;
• removing coatings on two ends of each of said optical fibbers;
• removing coatings on central portions of said optical fibers to be fused;
• securing one end of said fiber strand to a first pulling stage and passing said fiber strand through said quartz tube;
• splicing said central portions to be fused to form a spliced portion;
• securing the other end of said fiber strand to a second pulling stage and clipping said quartz tube on a holding device;
• providing a heating device having at least one torch blowpipe capable of indirectly heating said spliced portion through said quartz tube;
• coupling an optical source to said one end and connecting said the other end to an optical detector;
• igniting said torch blowpipe, reciprocatingly moving said torch blowpipe along said quartz tube, and moving said first and second pulling stages in a mirror-image symmetrical manner for oppositely pulling said fiber strand at its two ends while said quartz tube remains stationary;
• interrupting heating of said at least one torch blowpipe when a desired output ratio of said optical fibers is detected by said detector;
• and
• filling an adhesive through two ends of said quartz tube for adhesively incorporate said fiber strand with said quartz tube.