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University is a place where researchers have the freedom to discover new knowledge and to innovate. Hence, in line with this, academicians and researchers are the pillar of strength of our foundation in the University of Malaya (UM).


Fiber Drawing Tower Facilities-The Heart of Malaysia Multidisciplinary Research


By: PROF. DR. FAISAL RAFIQ BIN MAHAMD ADIKAN

The group is exploring this exciting field, involving the design, fabrication and characterisation of PCFs to be applied mainly in sensing applications. Fabrication of hollow core fibers has been successfully demonstrated recently and the aim is to investigate non-linear properties for use in biosensing. Photonic Crystal Fibers (PCFs) are a special class of optical fibers which demonstrate periodic microstructure in their cross section, normally consist of organized, micron-sized cylindrical holes extending in the axial of the fibers. PCFs are also known as Microstructured Optical Fibers (MOFs) or Holey Fibers (HFs).
The invention of PCFs was motivated by the ability of trapping light inside an air-filled hollow core fiber with a two-dimensional transverse photonic crystal structure in the cladding. Considered as one of the most active fields of current optics research, PCFs provide many degrees of freedom in their designs to achieve a variety of special properties, which make them interesting for a wide range of applications. PCFs can be divided into two main categories depending on the physical mechanism that facilitates light guidance. One type of PCF operates by the Modified-Total-Internal-Reflection (M-TIR) principle and has a solid core surrounded by a periodic lattice. The other type of PCF operates based on the Photonic Bandgap (PBG) effect. PBG PCFs possess a periodic cladding and a hollow core in which only some frequencies are allowed to propagate. PCFs have been successfully produced by a number of distinct methods.
Generally, they involve preparing a macroscopic meter-length preform with the desired transverse crystal lattice pattern, followed by pulling the preform in high temperature radiation heating furnace to produce microscopic-scale fibers while preserving the intended cross-sectional design. Examples of typical PCF fabrication methods include stack-and-draw, extrusion, sol-gel casting, injection molding and drilling. The most common method is stack-and-draw, devised by Knight et al. in 1996, the process is relatively fast, clean, low-cost, and flexible. ILRG is producing PCFs using stack-and-draw process.
This method begins with fabricating capillaries of required sizes with specific inner wall over outer wall diameter ratio (ID/OD) based on PCF hole diameter over lattice spacing ratio (d/pitch) determined in design. The fabricated capillaries are arranged into triangular lattice using custom-made jigs. By using fiber draw tower, the assembled PCF preform was pulled into standard fibre format by adjusting carefully the feeding rate, tractor speed, vacuum pressure and furnace temperature. This new and patented technology combines the advantages offered by the optical fiber and planar format. The research is aimed at creating fully flexible glass optical chips, and novel photonic crystal structures within the cross section of the Flat Fiber samples. These samples will find applications in distributed multi-point sensing, data transport, and fiber based lighting. The novel Flat Fiber was developed and patented in the Southampton University Optoelectronic Research Centre. The remarkable fiber was developed using the expertise that combines the advantages of the fiber technology and integrated optical devices.
The advantages of using established fiber manufacturing technique makes the next generation technology a low cost function. Designing a high sensitive irradiation dose sensor would be very useful for many applications especially when it is related to the human health such as radiotherapy that is used for treating cancer, removing tumors, or similar applications. Different dosimeter sensors with different sensitivities have been developed by combining different materials sensitive to radiation based on their application. Recently, optical fibers are shown to be a good alternative dosimeter sensor for different radiation sources such as electron, photon, alpha, neutron, synchrotron, and etc, from very low to very high dose ranges. This interesting property of optical fiber in detecting radiation dose is mainly due to the small germanium doping concentration in the core of standard optical fibers. While, a pure silica optical fiber is usually insensitive or very low sensitive to radiation dose.
The purpose of this proposed project is to develop an alternative low-cost dengue virus diagnostic chip that is inexpensive, fast and easy to use at the POC. The project is based on optofluidic compact chip-based for the detection of the dengue virus in a small volume of blood (<10�Liters) taken from dengue patients.


For more information on the research, Please contact: PROF. DR. FAISAL RAFIQ BIN MAHAMD ADIKAN
Last Update: December 05, 2014