Fiber Cleavers

Author: the photonics expert Dr. Rüdiger Paschotta (RP)

In fiber optics, it is often necessary to prepare clean surfaces for optical fibers. This is often done by cleaving, i.e., by controlled breaking. Instruments used for that purpose are called fiber cleavers.

For general aspects of cleaving, such as basic principles, problematic cases and the inspection of cleaving results, see the article on fiber cleavers.

Simple Cleaving Blades

The simplest cleaving method uses only a diamond blade, incorporated into a pen-shaped scribe, with which one manually makes a tiny scratch on the fiber, in a direction perpendicular to the fiber axis. (Note that too strong scratching can spoil the results.) One then holds the fiber on one end and gives the other part a kick with a finger, so that the cleave occurs. Alternatively, one may pull the fiber. Such techniques require some practicing, and the results are somewhat variable.

Simple and inexpensive mechanical cleavers can be part of fiber termination kits. They produce less consistent results than high-quality precision cleavers, as described below. At least, their use requires more practicing, and normally such devices are applicable only to standard silica fibers.

Precision Fiber Cleavers

Cleaving techniques with more controlled conditions allow for more consistent results. For that purpose, there are special apparatuses, called mechanical precision fiber cleavers, which work as follows:

• The fiber is inserted into the cleaver (after stripping its coating) and fixed, typically with a V groove and two clamps.
• By turning a handle, one then applies a tension, the magnitude of which can often be adjusted (e.g. with a screwdriver). That tension alone is not sufficient to break the fiber.
• With a second handle, one now carefully lets a diamond blade approach the fiber, causing the required scratch. The blade may be made vibrating with a small electromagnet or piezo.
• Finally, the tension is increased so that the fiber breaks.

With some cleavers, the tension during application of the blade is already high enough for the fiber to break.

There are versions of mechanical semi-automatic fiber cleavers which also allow for angle cleaving (see Figure 1), i.e., for preparing fiber ends with some angle against the fiber axis. For that purpose, the fiber is somewhat twisted before it is cleaved. Tentatively, stronger twisting leads to larger cleave angles, but that relation also depends on the tension, and there can be a substantial variation of cleave angles from try to try.

The direction for reflected light is also shown; it will not go back to the fiber core.

Some precision fiber cleavers are part of fusion splicing apparatuses, as precision cleaving is a prerequisite for successful splicing.

More to Learn

Suppliers

The RP Photonics Buyer's Guide contains 29 suppliers for fiber cleavers. Among them:

Fibercore

Fibercore has delivered over 40 years of innovation and excellence in developing and manufacturing specialty optical fiber. All of our fiber products have been developed with our customers in mind with market leading capabilities to produce an extensive range of fibers including;

• single-mode (SM) fiber
• doped fiber
• polarization-maintaining (PM) fiber
• multimode (MM) fiber
• multicore fiber
• spun HiBi fiber

We are continuously expanding our product ranges to cover wider and more demanding customer applications. So if you have a specific development project or require a custom fiber, we would like to discuss it further with you. We will work together with you to find the best solution.

NYFORS

The AUTOCLEAVER series is a comprehensive product platform with various models for cleaving standard and large diameter optical fibers, all based on our proven and patented tension and scribe cleaving process. Different models are carefully optimized for precision cleaving of standard, specialty and large diameter fibers with cladding diameters between 80 and 1000 μm. A common feature is the automated cleaving process intended to provide consistent results and high production yield in volume manufacturing environments. Low maintenance requirements ensure trouble-free operation during long periods of operation.

We have an open interface for integration into automated production systems. Fiber holder solutions are available for use with fusion splicers from Fujikura, Furukawa/FITEL and Vytran. Dual fiber holder positions for comfortable use with FSM-100 fusion splicers.

See our cleaver comparison sheet.

Questions and Comments from Users