Optical fiber coupler is a directional coupler which is crucial component for optical fiber communication systems.
The fused biconical taper is the most important method in facture of optical fiber coupler, with many advantages of low
excess loss, precise coupling ratio, good consistency and stability.
In this paper we have introduced a new method to manufacture optical fiber coupler. And more over the new
manufacture process has been compared with the traditional manufacture method. In the traditional crafts, two optical
fibers are parallel placed, and then use the method of tie a knot of the two optical fibers. In the new process, a new
program of fiber placement is introduced. Two optical fibers are parallel placed in the middle of the fixture, and then in
order to make the bare part of the optical fiber close as much as possible, the new plan using high temperature resistant
material bind the both end of the fiber which are not removing the cladding. After many contrast tests, we can see that
adopt the improved method of fiber placement, during the process of fiber pulling, the variation of optical power in the
directional arm and the coupler arm are more smooth and steady. But the excess loss (EL) generated in the process of
pulling is a bit higher than the traditional method of tie a knot. The tests show that the new method of optical fiber
placement is feasible in the actual projects for the manufacture of coupler with low coupling ratio, but for the control of
the EL still need further studying.