Knowledge, skills and care are as essential as proper tools and components.
by Jim Hayes, The Fiber Optic Association
The number-one rule of fiber-optic installation is never, ever try to install a new type of component or undertake a new type of application without proper training. Not having the knowledge or skills related to that component or application makes it virtually impossible to ensure success on the job, and mistakes can be very expensive. At The Fiber Optic Association we have lots of examples of installations that went wrong with terrible consequences.
No one can know everything, nor can any training course possibly cover all aspects of fiber optics, all types of components and applications. The technology is always advancing anyway, making it important to continue gaining knowledge from all available sources. Much of the technical knowledge needed can be obtain from Web sites, such as the FOA Online Reference Guide, but what about the skills needed for working with actual fiber-optic components for installation, testing, troubleshooting and restoration? Those skills can only come from training and experience.
Getting more training
What kinds of training are necessary for success as a fiber-optic contractor or installer, and where can you obtain that training? There are many options for further training, but first you need to figure out what your needs are, what training should include and who can provide appropriate training. As a general rule, all training in fiber optics that is aimed at installers must include sufficient hands-on activities with relevant equipment, tools and components for the student to develop skills appropriate for that activity.
Many training opportunities are available to fiber technicians learning to work with new components, equipment and applications. Product manufacturers, independent training organizations and many colleges and universities provide learning opportunities specific to fiber optics.
Fiber-optic technicians with some experience can often learn how to install many new component types or how to operate new equipment on their own. On websites of the FOA and many manufacturers, there is tutorial information on most installation subjects and in some cases “virtual hands-on” (VHO) tutorials on how it’s done, step-by-step. Most manufacturers have good instructions and often tutorials online to help. Given proper tools and applications information, the astute technician should be able to learn new processes in a short time. The secret, of course, is to do this in a quiet, clean office environment before trying it on a customer’s site with them looking over your shoulder.
Sometimes it is better to take a course. Many schools offer advanced or specialist courses in termination, splicing, testing, fiber-to-the-home and other studies that provide several days of intensive training, furnishing tools, equipment and supplies, as well as instructors who are familiar with the processes being taught. Manufacturers also offer product-specific training, but one should try to get trained by applications engineers, not sales personnel who may not have the depth of knowledge needed to adequately train installers.
Learning to install new components
There are hundreds of different types of fiber-optic components that manufacturers have developed for specific applications or to simplify the job of the installer. Many of these components are unique to the manufacturer and may require special tools and installation processes. Examples are prepolished/splice connectors, hot-melt-style connectors, splice closures, all-dielectric self-supporting cables, optical power ground wire, prefabricated cabling systems and others.
Generally one should go directly to the manufacturer for training like this unless an independent trainer has been trained and is recommended by the manufacturer. That trainer should have the proper tools and components to teach the processes required. Some manufacturers offer short introductory courses on their new products, which includes limited hands-on time, and such training may be ideal for those interested in learning more about that product before committing to purchasing all the tools and components necessary to use it. Follow-on comprehensive training can be done after making those purchases.
New equipment and applications
Some of the equipment necessary for fiber-optic installation is complicated and may be difficult to learn how to use without proper instruction on the same piece of equipment. Examples are automated fusion splicers, especially ribbon splicers, cable-pulling or plowing equipment and optical time-domain reflectometers (OTDRs).
Some of these pieces of equipment are quite complex and have peripheral products that must be used properly in conjunction with them to achieve the expected results. Ribbon splicers, for example, use ribbon strippers and cleavers, both of which are critical to achieving consistently good splices. All automated splicers have unique programming features so one needs to learn how to operate the splicer unit itself as well as how to make splices using it.
OTDRs are also complicated devices and learning to use them is a two-part process: learning how to operate the OTDR with all its options, and interpreting the data it takes in testing a fiber (the “trace” or “signature” as it is called). While all OTDR manufacturers offer “automatic testing” options, one cannot afford to trust them in all uses as they can easily become confused by artifacts like ghosts. The user should always manually check the OTDR trace to ensure proper conclusions from the test data.
Training needs to be done on the actual type and model of equipment of interest, as different manufacturers’ products or different models from the same manufacturer may have unique features. To be effective, the training must include two phases: how to set up and operate the equipment itself, and how to complete the processes for which it is intended. Generally manufacturers offer training on these products and independent trainers may use the same equipment or will be willing to train you on your equipment if you have already purchased it.
A point we make often is that there are many different applications for fiber optics and there are substantial differences in how those applications are designed, installed and tested. Outside plant technicians, for example, generally terminate by splicing on factory-made pigtails, while premises technicians terminate directly on fibers with adhesive/polish or prepolish/splice connectors. Fiber-to-the-premises technicians may only use prefab cable assemblies. Technicians moving from one application to another may require training as well on-the-job training (OJT) to understand the application and develop the appropriate skills.
Finding appropriate training
Whatever your interest, make sure the courses you take are appropriate for those interests or you’ll be wasting time and money. Following are some questions to ask and options to consider.
Can you learn it yourself? Some of us just learn better on our own. Is information on the topic readily available? Good videos can help too, especially with hands-on topics like cable pulling and termination. Can you get the right tools and components to use in developing the skills necessary? Is there someone you can call for assistance?
Does the manufacturer offer training? Does it cover what you need to know? Does it offer lots of practice with the equipment and components? Will you be certified as an approved installer for that manufacturer? That can help in getting business from customers of that manufacturer.
Do independent trainers, like FOA-approved schools, offer training in this area? Does it cover what you need to know? Does the trainer have the latest version of the equipment needed for training? Will they train you on your equipment? Is the instructor experienced and well-versed on the products and technology? Can the trainer offer manufacturer certification as well as other certifications?
Where is the training being offered? Travel costs can add significantly to training costs.
Outside plant safety is a very important issue, well beyond the usual fiber issues of protecting your eyes from fiber shards or working with potentially hazardous chemicals. Routes should be cleared with “One Call” or “Call Before You Dig” services to ensure no buried cables or pipes are in the proposed route. Installers working with cable-placing machinery need to be well trained in how to operate them safely. Aerial installations are particularly dangerous, since poles usually have electrical cables nearby. Every OSP job should have posted safety procedures and all personnel briefed in their use.
Safety in the lab or on the job site must be the number-one concern of everyone. Besides the usual safety issues for construction, generally covered under OSHA rules that should be familiar to all contractors and installers, fiber optics adds concerns for eye safety, chemicals, sparks from fusion splicing, disposal of fiber shards and more. Before beginning any installation, safety rules should be posted on the classroom wall, lab wall or on the job site and reviewed with all on-site personnel. All personnel must wear the usual construction safety gear plus everyone must wear eye protection whenever working with fiber.
Many people are concerned that the most dangerous part of fiber-optic work was the chance you might get your eyes harmed by laser light in the fiber. They had confused communications fiber optics with fiber optics coupled to the output of high-powered lasers used to cut metal, burn warts off skin at the doctor’s office, or perhaps they have seen too many science fiction movies.
In fact, most fiber-optic systems do not have sufficient power to cause harm to your eyes and the light coming out of a fiber is expanding, so the farther you are away from the end of the fiber, the lower the exposure. Having said that, consider yourself warned. In more recent times, some fiber-optic systems are carrying sufficient power to be dangerous, and some fiber-optic inspection techniques that might be used on operating systems increase the chance of harm. But that is not the biggest danger facing installers.
The key to understanding the power issue is understanding power levels, wavelength of the light and the nature of light transmission in optical fiber. Fiber-optic medical laser systems used for surgery and laser machining systems certainly have enough power to cause harm to your eyes, as well as burn off warts or machine some types of materials. Those systems use very high-power lasers, often CO2 lasers, which emit radiation at a wavelength that is really heat, not light—around 10 microns. This wavelength is readily absorbed by materials and can heat them quickly, cutting those materials easily.
Fiber-optic communications systems use much less power. First of all, most sources used in fiber optics are optimized for modulation speed, not absolute power. Premises cabling with multimode fiber and light-emitting diode (LED) sources has very low power levels, too low to be a hazard. Higher-speed premises links use vertical-cavity surface-emitting lasers (VCSELs), which are still quite low in power levels and generally harmless. Most telco links use lasers with power levels slightly higher than VCSELs.
Two types of links have high power, as much as 100 times more than other communications systems. They are cable TV or video links at 1550 nm and telco long-distance links using dense wavelength division multiplexing (DWDM). The cable TV or video links used in fiber-to-the-home may use fiber amplifiers that boost the power to very high levels, potentially dangerous to the eye. Telco DWDM links are used on extremely long-distance links. They not only use fiber amplifiers for boosting the power, but they have many different signals operating at different wavelengths carried in one singlemode fiber. Any one wavelength may not be a problem, but the sum of 16, 32 or 64 individual wavelengths can be very powerful.
The next issue is focusing the light from a fiber into your eye. Light exiting the optical fiber spreads out in a cone, the angle of which is determined by the transmission characteristics of the fiber as determined by the numerical aperture. As your eye gets farther from the end of the fiber, the amount of radiation it receives is inversely proportional to the square of the distance; double the distance and cut the power by ¼, ten times the distance reduces the power to about 1 percent. You do not have to be far away from the fiber for the power to be reduced to low, harmless levels.
Because the light is exiting the fiber in a cone-shaped beam, the eye cannot focus it on the retina. This is unlike the typical lab laser or laser pointer that shines a narrow, collimated beam that does not spread out; that is the type of beam your eye can easily focus on the retina, causing temporary blindness.
Finally, there is an issue of wavelength. Your eye cannot see many of the wavelengths used in fiber optics because the eye is sensitive to light in the blue to red region of the spectrum, while fiber-optic systems operate in the infrared (IR). The liquid in your eye, which is mostly water, absorbs light in the IR heavily. Light from most fiber-optic sources will be absorbed by this liquid, so any potential harm is likely to come to the lens or cornea, not the retina.
While the expanding beam of light exiting the fiber makes it less of an issue for direct viewing, using a fiber inspection microscope can be a problem. A microscope will focus virtually all the light back into the eye. Many microscopes used in fiber optics, therefore, have filters to absorb any IR light that could be harmful. Be wary of inexpensive microscopes that may not have IR-blocking filters.
To be certain fibers are safe to inspect or work with, always check fibers in an operating network with a fiber-optic power meter to ensure no light is present before inspecting any connector with a microscope.
Bare fiber safety
Fiber-optic installation is not without its risk. The more common problem is getting scraps of fiber in your eye. While few fiber-optic systems have harmful levels of power, every termination and splice produces shards (scraps) of optical fiber, which are potentially very harmful to your eyes and skin. Or they may stick into your clothing and be carried to other locations where they may harm others.
These shards of fiber are tiny, thin and often very sharp where they broke off the fiber. They can easily puncture your skin, burying themselves deep enough to be difficult to pull out, if only you could see them. Being transparent, they practically disappear once embedded in your skin. In most parts of your body, they merely become a nuisance, perhaps infecting or causing an irritating bump until they eventually work themselves out.
Around your eye, however, they can be much more difficult to find and remove. The tears that wet your eyes make the transparent glass shards practically impossible to find and remove. The sharp ends of the fiber may cause it to embed itself in the eye or surrounding tissue, making it even more difficult to remove. Unlike metallic particles, they cannot be removed with magnets.
It is imperative to follow procedures that minimize the dangers to the eye. Always wear protective eyewear with side shields, even if you normally wear glasses, to prevent any flying shards from getting near your eyes. Be extremely careful whenever handling fibers, especially when stripping fiber or scribing and breaking fiber extending out of an adhesive connector. Instead of breaking it, scribe it gently, then slide your fingers up the connector ferrule, grasping the fiber and pulling it off. Then dispose of it carefully.
Most cleavers used for splicing or terminating prepolished/splice connectors hold the fiber after cleaving, so the only problem is disposing of it. We recommend using disposable containers like those used for soups at carry-out restaurants. Use it for all your fiber scraps and then seal it and dispose of it properly.
You can also set up your workplace to make it easier to avoid problems. Use a black plastic mat for a work surface. The dark background will make it easier to see the fibers you are working with and handle them more carefully.
Jim Hayes is co-founder of The Fiber Optic Association (FOA; www.thefoa.org). He has more than 30 years’ experience in fiber-optic communications. This article is excerpted from Hayes’s most recent book FOA Reference Guide to Fiber Optics: Study Guide to FOA Certification, published by The FOA.
Additional considerations for safety
Chemicals: Fiber-optic splicing and termination use various chemical cleaners and adhesives as part of the processes. Technicians should observe normal handling procedures for these substances. Even simple isopropyl alcohol, used as a cleaner, is flammable and should be handled carefully. Manufacturers will supply material safety data sheets (MSDS) on request or they may be found on the Internet.
Splicing hazards: Fusion splicers use an electric arc to make splices, so care must be taken to ensure no flammable gases are present in the space where fusion splicing is done.
Smoking: Smoking should also not be allowed around fiber-optic work. The ashes from smoking contribute to the dirt problems with fibers, in addition to the possible presence of combustible substances—and, of course, the health risks.
Electrical hazards: Installation of fiber-optic cabling does not normally involve electrical hazards unless the cable includes conductors. However, these cables are often installed in proximity to electrical and conductive cables. Whenever you are near the cables, there is always a potential shock hazard. Be careful. If you are not familiar with electrical safety, we recommend you take a course on the National Electrical Code and safety practices for installers.