The development of a novel fused bi-conical taper machine with an electrical resistance micro-heater

Fused biconical taper (FBT) is a general manufacturing method to fabricate optical fiber coupler, splitter, WDM and other optical fiber devices. At present, the fused temperature was obtained by high-purity gas flame for fused taper machine. However, the problems occurred that the temperature from gas flame is vulnerable to environmental interference and drifts seriously. To overcome the problems and to improve the performance consistency of the optical fiber devices, a micro-heater is designed and manufactured using a metal-ceramic (MoSi₂) as a heating material which can be heated in the air above 1700 °C directly. A ceramic thermal insulating layer for the heater is also designed. According to temperature control theory and functional requirements of the heater, control circuit system of the power supply is added. The experimental results show that the temperature fluctuates only by 1 °C when the circuit uses PID control. Based on the electrical resistance heater, a fused biconical taper machine, which consists of mechanical motion systems, optical power detection system, computer control system and temperature control system, is developed. The experimental data show that the fused machine with the heater can improve the performance consistency by ten times than the previous one with gas flame.