There are four basic classifications of fiber termination: no-epoxy/no-polish, no-epoxy/polish, epoxy/polish and pigtail splicing.
No-epoxy/no-polish connectors offer the easiest and quickest termination technology available. Installers only need to strip, cleave, and lock the fiber into the connector body, which also contains a short pre-polished fiber stub in the ferrule. In effect, this is a connector with a built-in mechanical splice and a high-quality, factory-controlled end face that provides excellent return-loss performance for a field-terminated connector.
These connectors are ideal for locations with low-fiber-count terminations, such as small building backbones and work area outlets, or for maintenance, repairs, short moves, small adds, and quick changes. Installers with high labor rates, inexperienced technicians or an inconsistent work force will like the fast training and quick installation and the fact that only a short length of slack fiber is required for successful termination. Recent cost models have shown that this connector technology can be the most cost-effective for field installation.
- Shortest set-up and takedown time
- Shortest installation time per connector
- Lowest consumables costs
- Minimal training
- Setup: Essentially none: hand-held tools, no curing ovens to warm up, no power and no consumables.
- Installation: Less than one minute per fiber, regardless of the number of terminations.
- Materials: Highest cost per connector kit since some of the labor (polishing) is done in the factory, but likely to have the lowest labor cost. Some connectors require special tools, but the tools are usually handheld and comparatively inexpensive.
- Skill: Minimal amount of training is required to learn the “strip, cleave and lock” procedure, thus installations can more quickly utilize inexperienced labor without as much sensitivity to the installation process. This type of connector is ideal for installers with a high turnover rate of technicians or that do limited numbers of optical-fiber terminations.
No-epoxy/polish connectors replace the need for epoxy by using a crimp or clamp mechanism to lock the fiber in the ferrule. The excess fiber is then cleaved at the end face and hand-polished to produce a working connector. This is a popular choice for installers because it eliminates two of the industry’s primary complaints about fiber terminations: the need to mix and apply epoxy and the need for a curing fixture (ovens or lamps that require power).
No-epoxy/polish is ideal for locations with moderate fiber-count cables or for companies that perform a mixture of backbone and FTTD projects. It is easily adaptable for high-fiber-count and low-fiber-count locations and ideal for installers with moderate labor costs and a reasonably stable, trained work force because it offers the maximum flexibility with one technology, and a good balance between material and labor costs. Recent cost models have shown that the no-epoxy/polish technology can be very effective when compared to epoxy/polish terminations.
- Moderate material cost
- Moderate capital investment in tool kit
- Moderate installation time
- Setup: Takes about nine to 15 minutes at each location to set up the polishing station.
- Installation: Takes about five to ten minutes to lock and polish each fiber.
- Materials: Moderate cost for the connector kit, but there is no need for an oven or for epoxy or adhesive which can be an expensive consumable. A polishing kit is required as are the appropriate fixtures for the connector type, the polishing papers and fluid consumables. Thus, there is a moderate capital investment and consumables cost.
- Skill: Although the locking mechanism is essentially the same for the no-epoxy/no-polish technology, the amount of training and skill is increased because of the polishing procedure which takes a bit of time to develop a “feel” for how it is done. ceramic ferrule for fiber termination in four easy steps. Just strip the cable, strip the fiber, crimp on the connector, and polish. Multimode LightCrimp connectors work for 50-micron, 62.5-micron and XG (850nm LO 50-micron) fiber terminations. A single-mode version is available for ST.
Today, there are two options for this technology: heat-cured, which requires 20 minutes or more in an oven, and quick-cure, which uses and fast-setting epoxies like cyanoacrylates. Both methods are suitable for terminating highfiber-count cables in a single location. In these situations, the longer setup time and curing time can be offset by establishing an assembly-line type of process – while some connectors are being polished, others are in the curing process. The process takes some experience to get proficient but can yield some of the lowest loss terminations. So, it’s an excellent option for installers with low labor costs and a stable, trained work force.
Obviously, however, setting up a curing and polishing station at every work area is too cumbersome and timeconsuming – particularly in cramped and difficult-to-access locations like under a desk. The faster-curing adhesives considerably reduce the curing time, often to within two minutes without the need for an oven or power source, but are more expensive and must be used quickly once opened and have a short shelf life even if unopened.
- Lowest connector kit cost
- Can offer the best performance (lowest loss, lowest reflections)
- Setup: Takes approximately ten to 15 minutes per location, because the adhesives must be prepared and the polish station must be prepared before starting.
- Installation: Takes as long as 25 minutes for a single connector but can be an average of six minutes each for a large number of connectors in a single location.
- Cost: This has the lowest connector kit cost, but does require a separate investment in a curing oven and polishing station. Additional consumables costs for the adhesives, fluids and polishing papers must also be considered. For these reasons, the epoxy-polish connectors are economical if these costs can be spread across a large number of connectors and if waste is kept to a minimum.
- Skill: Although the technique is not difficult, it does require the most training and skill, specifically in the application of the adhesive and the polishing of the connector. These skills take time to learn and master and must be taught and acquired to produce consistently good results. Accordingly, this technique is most suited to installation companies with a trained work force, low turnover rates, and low labor costs. Due to the time required, high labor rates can adversely affect the cost-effectiveness of this technology.
Pigtail Fusion Splicing
Some installers opt for another termination altogether. Rather than terminate the fiber in the field, they fusion splice a pigtail (basically, one end of a factory-made patch cord) to the installed fibers. Worries about epoxies, hand tools or curing times are eliminated; however it does require the use of a fusion splicer to join the fiber in the pigtail to the installed fiber.
Pigtail splicing makes the most sense for installers that have already invested in a fusion splicer. The compact fusion splicers available today are smaller and less expensive, but still represent an investment of several thousand dollars. Renting these units is often economical for a few days or less. Installation can proceed quickly and the results can be as good as the epoxy-polish connectors. Since pigtails and patch cords are often mass-produced in the factory, the cost is slightly higher than the epoxy-polish connector kit but doesn’t require the assembly and termination labor and thus can offer the best performance for the individual connector. However, there is an additional loss associated with the fusion splice and additional hardware is needed to house the splices or heat shrink splice protectors. This technology works best for installers working with a large number of fibers, or on high-performance single-mode networks.
Pigtail Splicing Advantages
- Low material cost
- Readily available parts
- Good loss and reflection performance
Pigtail Splicing Comparison
- Setup: Takes about five minutes at each location to set up the fusion splicer. A power source (or an extension cord to one) is usually required, although many fusion splicers have some inherent battery power. Some fusion splicers require a warmup period of several minutes.
- Installation: Takes about five minutes to prepare and fuse each fiber, then protect the splice.
- Materials: The biggest cost is the capital and maintenance costs of the fusion splicer. Once this capital investment is made, however, each subsequent use reduces the net cost per termination. Each splice must be protected, either with a heat shrink or sealant and must be housed in separate trays; both add to the materials and real estate (rack space) costs of this method. Pigtails must be purchased separately, but are often available at low cost from several large-scale vendors. Keep in mind that the quality you pay for is the quality that is installed – so buy from reputable and traceable suppliers. Thus, there is an extensive capital investment but minimal consumables cost with this technology.
- Skill: Using a fusion splicer takes training and skill, but modern fusion splicers make it easier to get good results once the fiber is loaded into the machine.
From AMP TE