Fiber-Optic-Fusion-Splicers

Fiber-optic-fusion-splicers automatically control splicing the ends of two bare optical fibers together. They are easy to use and require minimal maintenance, but do have specific operating requirements.

Fusion splicer calibration ensures proper alignment of the joined fiber cores, which minimizes reflections and increases network performance. Regular calibration prevents costly downtime due to improper splice losses.

Preparation

Before fusion splicing, technicians must perform a thorough inspection and cleaning of the fibers. Cleanliness is essential to ensuring low-loss splices, as contaminants like dirt or oil can cause loss or even breakage. This process involves removing the protective polymer coating with a stripper, and fiber-optic-fusion-splicers it is important to follow the splicer manufacturer’s instructions for specific details regarding how much of the polymer should be stripped. It is also necessary to properly prepare the spliced end of the fiber by passing it through a heat-shrinkable sleeve, which protects it from mechanical stress and environmental factors.

Once the fibers are cleaned and prepared, a cleaver is used to trim the tips of each optical cable end to the correct length for insertion into the splicer. The cleaver must be specifically designed for use with optical cables, as standard cutters or scissors can deform the fiber’s end face, causing high splice losses. A cleaver with a blade rotation and depth control features ensures a precise cut.

The fusion splicer is then used to align the two cleaved ends of the optical fiber, using movable stages and multiple cameras. The alignment process is critical, as the spliced end of the optical fiber must be perfectly perpendicular to its neighbor for a low-loss fusion joint. The spliced ends can be verified by an optical time-domain reflectometer (OTDR) or an optical power meter, and they should be documented for future reference.

Cleaving

The first step in preparing for splicing is stripping the fiber of any protective coatings or jackets, as well as cleaning the exposed ends with alcohol wipes. This is done to remove contaminants that will cause loss in the splice.

Next, the fibers are cleaved with a specialized tool that trims the end of an optical fiber at a precise angle. This requires a high level of precision since the resulting break must be mirror-smooth and perfectly perpendicular to the center of the fiber axis to obtain a good fusion splice. Most splicers come with these cleavers, or they can be purchased separately.

Once the cleaving has been completed, the splice is aligned and prepared for fusion. This is a critical process, as a poorly aligned splice can introduce substantial splice loss and affect the performance of a network. High-end fusion splicers use active core alignment, which uses light injection technology to precisely align the fiber cores, resulting in a low splice loss of 0.02dB or less.

More basic fusion splicers rely on clad alignment, which simply lines up the two ends of a fiber pair using the outer diameters of their cladding. This can be accomplished manually or automatically, depending on the type of splicer and its programming. This method is fiber optic components also less reliable, as the splices are only guaranteed to be properly aligned by their cladding, not their cores.

Alignment

The fusion process fuses the ends of two fibers together permanently, creating a low-loss connection that minimizes signal degradation. This is an essential requirement for high-bandwidth applications such as cloud computing, video conferencing, and stock trading. It is also highly durable and can withstand harsh environmental conditions.

A quality fusion splicer is designed to perform these tasks with precision and efficiency. It is able to accurately align the fibers and automatically melt them using an electric arc, producing a unified optical path that allows for optimal data transmission. It also offers a wide range of features for diagnostics and maintenance, including OTDR testing and easy-to-read displays.

Precise cleaving ensures the ends of the fibers have a flat end-face for optimum splicing and minimal loss. The splicer then uses an electric arc to fuse the fibers, producing a permanent, high-quality splice. The resulting connection is reinforced with a protective heat-shrink sleeve for additional mechanical protection.

Some fusion splicers use cladding alignments, where the spliced fibers sit in a V-groove or holder and are lined up “physically” based on their outer diameters. This type of splicer is suitable for single-mode or multimode cable, but it does not provide the precise core-to-core alignment required for high-performance fibers, which can result in elevated splice loss values when verified with an OTDR. To mitigate this, some fusion splicers utilize active core alignment systems that detect the core of each fiber and precisely align them, reducing splice losses by as much as 0.02dB.

Fusing

A fusion splicer uses an electric arc to melt the ends of two optical fibers together, creating a single, continuous path for data transmission. This process requires precision, as misalignment or impurities can cause a low-quality connection that limits the fiber’s transmission capabilities. Most fusion splicers include built-in features that help technicians inspect and ensure the quality of the splice. These can include a video camera or viewing scope for magnification, an optical power meter to monitor the light transmitted through the fibers, and automated alignment that fuses the fibers’ cladding and cores together while keeping their polarization-maintaining characteristics intact.

Once the splice is completed, a technician may insert a heat-shrink protective sleeve over the fusion splice to prevent moisture from damaging it in the future. The splicer also has an inspection program that sends a testing light through the fused fiber ends to evaluate their losses. If the losses are within acceptable limits, the device will beep to indicate that the splice is complete.

While a fusion splicer can provide an estimate of splice loss, the best way to test long concatenated cable lengths with multiple splices is to use an optical time domain reflectometer (OTDR). This device measures end-to-end loss by sending a pulse of light through the entire system and measuring the reflections caused by events like splices, connectors, or mechanical snags. The OTDR gives accurate, precise loss values for the entire cable, so it’s the preferred method for long, concatenated fiber cables.