A local researcher has proven his skeptics wrong by developing what is likely the world's first laser splicing technique to fuse optical fibers, whilst maintaining the high performance and reliability optical networking is renowned for.
In an era where the growth of the Internet has spawned the need for high-speed, high-capacity communications systems, optical fiber networking has emerged as the medium of choice since no other technology has been able to match its data transmission speed and capacity.
Fiber splicing has proven to be an important tool to form permanent joints between fibers, and has been extensively utilized in long-haul telecommunication fiber transmission links in local area networks and telecommunications systems.
When M. K. Rao, associate professor at the School of Electrical and Electronic Engineering, Nanyang Technological University (NTU), first broached the use of laser technique in fiber splicing, skeptics refuted it, noting that because laser is currently used to transmit data through optical fibers, it was not possible that the technique could weld fibers.
Current methods of fiber splicing include mechanical and arc-fusion techniques, which can affect the quality of joints and that of the transmitted signal, Rao explained. For example, the arc fusion technique requires the application of high voltage, emitting electrodes which produce vaporized particles that can contaminate the fibers, and cause performance degradation.
Rao then thought of laser because it is provides better control, and is "clean", so there is little risk of contamination.
The potential of laser technique in fiber splicing has never been explored before partly because optical fibers -- made of silica -- are transparent to light and absorb laser light in very small amounts, he said, noting that light absorption is needed to trigger the melding process in optic fibers.
In addition, not only was the implementation process complex, it was also difficult to determine the appropriate parameters for laser splicing, due to the nature of the fiber size which has a diameter of about one-tenth of a millimeter, he explained.
"Due to the small fiber size, it was difficult to align fiber-to-fiber and fiber-to-laser for the melding process," he said. "But I knew that if we could achieve the suitable parameters, it should be possible to do the splicing."
Rao then received funding from Singapore Telecommunications and NTU, and started the Laser Splicing Project, which involves the use of a controlled high-power laser beam to provide simpler, economical and efficient solutions to fiber splicing.
Numerous experiments later, Rao had determined the correct parameters, such as power and heat, and was able to meld optical fibers effectively through laser lights at a cost that is 30 to 40 percent lower than conventional methods. The advantages of laser splicing technique include the delivery of intense energy over a small area, localized heating, uniformity, and repeatability and precise control of the splicing procedure, he said.
The Laser Splicing Project also involves development of a computer-aided, field usable, laser-splicing system, which Rao's team developed, and is currently planning to include support for other platforms such as Linux. Rao has already received a U.S. patent for the laser splicing technique, and is currently considering patent application in Europe. Several companies have also shown an interest in bringing the technique to market.