Research on the Reliable Fabrication of Specialty Polymer Optical Fiber (POF) Using Continuous Extrusion Technique

Description

Plastic optical fiber (POF) has many physical and economical advantages that a glass optical fiber (GOF) does not possess, e. g., a large core diameter and numerical aperture (NA), superior flexibility, higher endurance to repeated bending etc. Hence POF is very useful in short distance communications such as local area or home networks. The conventional 'preform' method for the manufacture of GOFs has been adopted for the fabrication of POF. However, this method has the disadvantage that a finite length of fibre can be drawn. This adds to the cost of the fibre and the cost of frequent splicing of fibres. Plastic fibre has a much lower operating temperature and can be made from pebbles freely available in the market. Thus the early plastic fibre (step index large core) has been made by extrusion method by melting the plastic pebbles in a hopper and extruded through a nostril into fibre form. For communication purpose, high bandwidth fibre is important. This demands the fibre to be graded-index. Graded-index POF (GIPOF) by extrusion method has not been well-developed. It is one of the purposes of this research to develop this technology.POF's are not only useful for data communication, but they are also especially well suited for some specialty applications. For example, by using appropriate monomer materials, it can be used in high temperature environment with very tight bends, which are the essential requirements of automobile and aerospace industry. By incorporating light scattering particles into the POF during manufacturing or introducing surface micro-deformation, it can be used as illumination in the lighting of architectural and contour buildings, hotels and entertainment centers. The illumination fiber can also be added to fabric structures. But, the technologies are still in the development stage and reliable fabrication is a great concern. In recent years, many researches over the world are attracted only to reduce the attenuation or optical loss for data transmission purpose. However, the above-mentioned issues in such specialty POF systems are also very demanding and worthy of research. They obviously need the special requirement of POF materials and fabrication techniques, which are still not well known in details. Further development and characterization of such special POF is essentially needed to enhance the manufacturing process of POF industry. Therefore, the other objectives of this project are to investigate how the above mentioned issues can be implemented in POF systems. This will help to address the problems induced by the process and can greatly aid the selection of proper polymeric materials and process parameters in the fabrication of specialty POF to extend the applications.