Loss dependence on pull speed and pull delay of 3 dB fused tapered single mode fiber coupler

We present here results on the effects of various pulling speeds (PS) and pull delays (PD) for a fixed flame profile on the performance of 1×2 50/50 or 3 dB 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 in a speed range from 25 μm/s to 250 μm/s. It is also found that at a pull delay of 80 s, excess loss as low as 0.02 dB can be achieved