Fiber-Optic Cleavers and Scribes

Thorlabs offers the S90R ruby-tipped scribe, the CSW12-5 ceramic scribe, and the XL411 suspension cleaver as solutions for easy, manual cleaving of fibers. The S90R ruby-tipped wedge scribe can be used for easy scribing of excess fiber from ferrules in the connectorization process. The CSW12-5 ceramic scribes are optimal for scoring and cleaving hard-coated and large-core fiber. The XL411 suspension cleaver is an ideal solution for the high-quality, repeatable cleaves needed for fusion splicing of fiber optics. The FTDU provides a simple safe solution for disposing of all cleaved fiber ends. We recommend using such a disposal unit to protect against injuries caused by fiber shards. In addition, Thorlabs offers a variety of complementary products and tools for fiber termination.

Click to Enlarge
Figure 1: Hold the ruby scribe perpendicular to the fiber.

Click to Enlarge
Figure 2: Hold the ceramic scribe at a 45° angle to the fiber.

The S90R and CSW12-5 scribes are convenient, easy-to-use tools for scoring or cleaving fiber. They are used extensively when connectorizing or polishing fibers. Below is a simple step-by-step description on the most common usages for these scribes. For more detailed information on connectorization or polishing of fibers, please refer to the FN96A connectorization guide.

Fiber Scoring

Scoring is a technique for cleaving a fiber that utilizes a scribe to make a small cut in the fiber (i.e., a score) that becomes a stress point for cleaving. Below are descriptions on how to use the S90R ruby scribe and the CSW12-5 ceramic scribe.

For the S90R, the cutting edge of the ruby scribe must be held perpendicularly to the protruding fiber. Figure 1 shows a fiber, protruding from a connector, undergoing scoring by a ruby scribe. The
CSW12-5 ceramic scribe should be held at a 45° angle to the fiber so that the straight edge (i.e., any edge on the un-engraved side) is in contact with the fiber. As shown in Figure 2, this will result in the engraved side facing upwards. The engraved metric scale on the CSW12-5 can used to ensure repeatable cuts.

While restraining the fiber, gently drag the scribe across the fiber at the desired location. Different optical fiber types will require different amounts of scoring. It will not take a lot of force to score the fiber, and the fiber should not break during scoring. If the fiber does break during scoring, it may produce a jagged edge that cannot be polished correctly; hence, care must be taken to prevent breakage during scoring. Over time, as the cutting edge progressively deteriorates, more pressure will be needed to score the fiber; keep in mind that undue pressure can lead to poor cuts. Once a fiber has been scored, it can be easily cleaved. From the scored side of the fiber, gently squeeze the fiber tip and pull straight away from the rest of the fiber (see Figure 4). Avoid bending or flexing the fiber. This should be all the force necessary to create a clean cleave. Multimode fibers may require slightly more force due to their larger
core diameter.

Click to Enlarge
Figure 3: Ensure the fiber is secured and taut when cleaving or scoring.

Click to Enlarge
Figure 4: Pull the fiber straight back until the fiber is cleaved to ensure a clean break. Do not twist or bend the fiber.

Fiber Cleaving

Cleaving a fiber is a technique that is very similar to scoring. After preparing a fiber for cleaving, clean the bare fiber using a lint-free wipe moistened with isopropyl alcohol. Once clean, tape one end of the fiber to a bench or work station; leave about 6 mm between the edge of the table and tape. Figure 3 shows a fiber cable prepped for cleaving. When using this technique, it helps to secure the free end of the fiber to a support in order to help prevent against breaking the fiber on the edge of the table. Even the weight from a short section of fiber can be enough to cause the fiber to break.

To start the cleave, pull the fiber taut and keep tension in the fiber as you cleave. Bring the scribe toward the fiber at a 45° angle for the ceramic scribe (see figure 2) or at a perpendicular angle for the ruby scribe (see figure 3). It's important to keep the proper amount of pressure on the scribe during this process. If too much pressure is applied to the scribe, the fiber will break, resulting in a jagged end, which may not be able to be polished correctly. Too little pressure and the fiber will not score enough to cleave cleanly. After the fiber has been scored, place a drop of water on the cleave site. Then apply pressure to the taped end of the fiber and, like with the scoring above, pull the fiber straight back until you cleave the fiber (see figure 4). Try to avoid any bending or flexing of the fiber, as this could affect the cleave.

The end of the fiber may be inspected with an eye loupe or microscope. A good cleave will be flat across the fiber and perpendicular to the optic axis. There should be no 'tag' (i.e., protrusion) from the edge of the fiber. The region where the initial scribe was made may be visible. It should be less than 5% of the core diameter. If the cleave is not acceptable, repeat the cleaving process.

Click to Enlarge
XL411 Packaging

Smart Pack

• Reduce Weight of Packaging Materials
• Increase Usage of Recyclable Packing Materials
• Improve Packing Integrity
• Decrease Shipping Costs

Thorlabs' Smart Pack Initiative is aimed at waste minimization while still maintaining adequate protection for our products. By eliminating any unnecessary packaging, implementing packaging design changes, and utilizing eco-friendly packaging materials for our customers when possible, this initiative seeks to improve the environmental impact of our product packaging. Products listed above are now shipped in re-engineered packaging that minimizes the weight and the use of non-recyclable materials.^b As we move through our product line, we will indicate re-engineered packages with our Smart Pack logo.

• Travel-based emissions reduction calculations are estimated based on the total weight reduction of packaging materials used for all of 2013’s product sales, traveling 1,000 miles on an airplane, to provide general understanding of the impact of packaging material reduction. Calculations were made using the EPA’s shipping emissions values for different modes of transport.
• Some Smart Pack products may show a negative weight reduction percentage as the substitution of greener packaging materials, such as the Greenwrap, at times slightly increases the weight of the product packaging.