Development On A New Type Of Electrical FBT Machine

Fused-taper optical fiber devices are the most typical and basic optical passive devices, which are widely used in the field of fiber communication and fiber sensor. For most FBT (Fused Biconical Taper) machines, the fused temperature of fiber is obtained by burning pure gas, which is easily drifted and disturbed and hard to control. Therefore the stress interpolation of fiber is rising and the conformity of the performances of fiber devices is bad. Although the old electrical heater can overcome the disadvantages of the gas-burning method ,the popularization of its application is limited ,due to its series of questions ,such as structure . In this paper ,the pros and cons of the old electrical heater will be synthetically analyzed , based on which a new kind of electrical heater will be put forward as improvement ,and the new electrical heater will be embedded in the FBT machine by conformity and optimization that can promote the application of the electrical-burning method.The main research content is shown as below.In the paper, it is introduced the structures and functions of conventional FBT machines will be introduced briefly ,as well as the pros and cons of the gas-buring method and the old electrical heater.Based on this, the material and structure of the electrical heater will be improved. Especially on structure, a new kind of electrical heater will be designed and embedded in the FBT machine by conformity and optimization.Based on heat transfer theory ,the heat analysis model of electrical heater will be built. With the help of FEA software, the temperature and stress distribution of the new electrical heater are analyzed. Aiming at the electrical heater's existing questions such as high temperature oxidation ,assemble,line connection,heat insulation and so on, a new heater fixture and technics flow are brought forward.Then based on the above ,the temperature distribution of heater fixture will be analyzed and improved. Experiments are carried through on the FBT machine which has been embedded the electrical heater.To analyze the related laws between the drawing technics and optical performance such as insetion loss,excess loss,diectivity,uniformity and so on, the technical parameters such as fused temperature, drawing velocity, pre-drawing length and pre-heating time are confirmed. Lastly, a great deal of fiber couplers are analyzed and compared with the aspect of performance distribution, and the results show that the performance conformity of devices manufactured by new FBT machine are the same as the old one ,both better than that of the gas-burning method.