Abstract
We present here the results on the effects of various pulling speed's (PS) and pull delays (PD) for a fixed flame profile on the performance of 1x2 50/50 or 3dB Fused Biconical Tapered (FBT) single mode optical fiber couplers. We study how these factors correlate with the shape of the fused tapered region and therefore influence the coupler performance. The fabrication technique, which is based on the heat fusion of the twisted section of two standard single mode fibers of the same type are elaborated A good fiber coupler can be produced by pulling it at the speed range from 25 mu m/s to 250 mu m/s. It is also found that at pull delay of 80 second's, excess loss as low as 0.02 dB can be achieved.