As demand for broadband increases, the superiority of fiber optic data communications networks is recognized by enterprise organizations, smaller businesses and even individual homeowners living in areas offering direct fiber connectivity.
As the number of electrical contractors active in datacom work grows, demand for fiber systems also increases, and contractors experienced in fiber work understand that correctly terminating fiber optic cable requires specialized skills developed from training and experience, carefully following prescribed steps for making a termination, and using quality tools appropriate to the termination method.
Basic connection methods include adhesive, mechanical, prepolished and pigtail. A fusion-splicing machine is needed to connect the fiber being terminated to a fiber pigtail pre-assembled to a connector.
“There is such a variety of connectors used today, the hand tools used to install connectors vary depending on whether the termination is with epoxy, hot-melt, anaerobic, crimp-style or fusion-applicable connectors,” said James Dallas, manager of training for Kitco Fiber Optics. “Typically the crimp- style connectors will require specialty tools from the connector manufacturer.”
As for fiber tools, Dallas said there has been little change over the past two years, when Cool Tools last reported on this topic.
“As data rates continue to grow, end-face geometry becomes more critical, and back reflection values become an issue,” he said. “If you hand polish, then you will spend more time polishing to limit back reflection in single-mode fibers. Many technicians are going to prepolished connectors that are crimped onto the fiber. These connectors have already been polished to the proper back reflection values. Manufacturers of these connectors make their own specialty tools to install them.”
Art Tsubaki, Greenlee Textron’s director of optical fiber, also said there has been little change in fiber tools.
“What has changed,” he said, “is the way the technician can do things. Fiber cable companies provide jumpers or pigtails with connectors already attached at the factory, so the technician can cut, strip and clean one end and either mechanically splice or fusion splice an end on it. This speeds up the termination and installation and provides better accuracy and alignment than in the past. Hand tools are needed for some jobs, but the mechanization to have easily repeatable connections depends primarily on cable vendors that make these pigtails.”
Dennis Manes, senior applications engineer, Leviton Network Solutions, sees several trends in the datacom industry related to terminating fiber.
“We see a trend to increased use of prepolished terminations,” he said. “This is happening because of time and labor factors. Prepolished terminations are significantly less time-consuming, making workers more productive. They also provide better results, reducing the need to redo work. Most contractors know they can control material costs better than labor costs, so anything that can move product into the ‘controllable’ area is a step in the right direction.”
Adhesive connections remain the most common method of terminating fiber, Manes said, but the fastest growth is in the prepolished connector category.
Regarding tools needed to make terminations, Manes said Leviton does not see much evolution. However, he said, because prepolished connections require that cables be precisely cleaved, today’s cleaving tools provide a greater level of accuracy than older tools.
“Precision and ruggedness of tools also are improved,” he said. “And we see the cost between precision tools and those with lesser capabilities has narrowed significantly.”
While many fiber tools are limited to specific functions, some can be used for multiple termination applications.
“For example, the same jacket stripper is included in Leviton adhesive, prepolished, and mechanical kits,” he said.
Another evolution in the use of existing tools is using a visual fault locator tool to verify proper alignment and positioning of the fiber as it is being terminated into a prepolished connector.
“The tool is not new, but this application of it is new,” Manes said.
A critical element in making terminations is keeping ends of fiber clean.
In a Fluke Networks commissioned study, installers and private network owners both cited dirt and contamination as the number one cause of failure for fiber optic links, said Jason Tam, Fluke Networks’ product manager for fiber verification products. Broken connectors, mislabeled cables and shattered end-faces also were significant issues.
“The performance demands of fiber links have increased significantly in recent years. Loss budgets have tightened drastically,” Tam said. “Minor imperfections that may have performed adequately in the past will not pass today. The most common installation problem [is] fiber end-face contamination—-commonly from dirt, dust, smudges, bodily oils, even leftover residue from isopropyl alcohol.”
To combat dirt and contamination during fiber termination and end-face mating, installers need inspection tools and cleaning materials. Both have seen considerable alterations in the past two years, Tam said.
Inspection tools come in two main varieties: passive viewers and video microscopes.
“Passive fiber viewers are handheld microscopes that magnify the view of the fiber end-face so that dirt, fingerprints and other contaminants can be seen and eventually cleaned,” Tam said. “They are simple to use and relatively inexpensive. Passive viewers, however, have two disadvantages: They are hard to align with fiber ports, making it very difficult to see contaminants inside the port, and they may pass any laser from an active fiber through to the operator’s eye, posing a potential health risk to the user.”
On the other hand, video microscopes use a small probe connected to a viewing screen to provide detailed views of both fiber end-faces and the inside of fiber ports.
“Ease of use and user safety are two very strong arguments for video microscopes as essential tools for fiber installers,” Tam said. “Any harmful laser light on a live fiber reaches only the video camera, protecting the user from harm.”
As others in the industry emphasize, training is a critical element in ensuring correct fiber terminations. Manes said manufacturers are doing a better job providing a detailed level of instruction that helps convey how to correctly terminate the various types of fiber connections.
“The mystery of fiber is not as deep as it once was,” Manes said, “and it is now understood that proper training, following procedures and execution are the keys for installers being highly productive. We do everything we can to ensure our certified installers are trained in these methodologies up front.”
“There are a number of ways to be trained to become a fiber installer,” said Kitco’s Dallas. “Many of the community colleges are offering fiber courses. Connector manufacturers also will offer fiber training on their products. If you are looking for certification, you can contact the Fiber Optic Association or the Electronics Technicians Association. Both organizations have a number of companies and personnel accredited to train fiber optic installers or technicians. Their Web sites list approved training facilities and locations.”
Demand for fiber is not expected to slow in the immediate future.
“Eventually fiber is going to be installed to everyone’s home,” Dallas said. “The world is wrapped in fiber optic cable and until a new medium is introduced that will take us to a newer level in communications, we will continue to see the copper installations shrinking and the fiber installations continue to grow. New installations and developments are going all fiber.”
Tools for fiber will continue to evolve, Dallas said.
“There will always be changes and improvements,” he said. “Build a better mouse trap, and people will purchase it. When fiber optic connector and tool manufacturers come up with a faster, cheaper, more reliable and repeatable tool or connector, there will be a place for them in the market.”
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at firstname.lastname@example.org.