Choosing a Fiber Optic Cleaver

The old adage, “You get what you pay for” applies to most purchases that you make in life. Fiber optic cleavers are no exception!

 

When choosing a fiber optic cleaver there are two types of devices to consider:

 

• Precision Cleavers – These are used to prepare fiber for fusion splicing. This is a process in which a separate tool called a fusion splicer or fusion splicing machine uses a powerful electric arc to fuse (or splice) two fibers together. Precision cleavers also provide superior results when used to prepare fibers for mechanical splicing.

 

• Mechanical Cleavers – A mechanical cleaver is used to prepare fiber for mechanical splicing only. Instead of fusing, mechanical splices rely on mechanical gripping mechanisms to hold the two fibers together. Mechanical cleavers are not considered accurate enough to prepare fibers for fusion splicing. That being said, even low cost mechanical cleavers have their place.

 

This blog will help you decide which type of cleaver is best suited to your needs and budget.

 

Precision Cleavers Vs. Mechanical Cleavers

 

A Closer Look

 

Before an optical fiber can be spliced to another fiber, the end of the fiber must be prepared prior to splicing. The fiber endface must be cleaved, which means breaking (cleaving) the fiber in a precise manner that produces a cleaved surface with the proper geometry and smoothness to ensure optimum signal throughput after the splice is completed. The goal is to minimize light scattering and back reflection at the juncture of the two fibers.

 

The degree to which such accuracy can be achieved depends on whether you are using a cleaver meant for fusion splicing (precision cleaver) or mechanical splicing (mechanical cleaver).

 

Precision Cleavers

 

Precision cleavers are capable of producing a near perfect cleave in which the cleaved endface of the fiber is at a 90 degree angle relative to the length of the fiber, in other words after cleaving the fiber endface is perpendicular relative to the length of the fiber. Generally, this is the ideal angle at which to fuse two fibers together. Some precision cleavers are designed to produce cleave angles other than 90 degrees, such as may be required for specialized applications involved in the manufacture of semiconductors and laser diodes. Angled cleavers are also sometimes used with mechanical splices to minimize back reflectance.

 

In either case, the goal is to achieve consistent cleave angles within 1 degree of accuracy, this can only be achieved using a Precision Cleaver.

 

Operation

 

When using a precision cleaver, the technician simply places the fiber in the device and clamps it down in the correct position. The tool then completes the cleaving operation automatically. There is no chance that the operator will apply the wrong amount of pressure to score and snap the fiber. The precision cleaver does it all, with accuracy, repeatability and reliability.

 

Applications

 

• Single mode and Multimode Networks

• Telecom and Datacom

• Component Assembly

• High Strength Splicing Applications

• Splice-On Connectors

 

Advantages

 

• Cleaves both single mode and multimode fiber

• Produces high precision cleaves that mitigate signal loss

• Provides reliability and repeatability

• Ribbon splicing option

 

Disadvantages

 

• Cost - Relatively high cost compared to mechanical cleavers. Typical prices range from $500 to $1,000 or more.

 

Mechanical Cleavers

 

If your application allows splicing fibers by mechanical means (as opposed to fusing them together) you can probably get by with a relatively inexpensive mechanical cleaver. Mechanical cleavers are used to prepare fibers for mechanical splices, which employ mechanical gripping mechanisms to hold the two fibers together. Mechanical splices may also use Index Matching Gel between adjoining fibers to help reduce back reflection and signal loss due to irregularities in the fiber endfaces. Mechanical cleavers are also known as pocket cleavers, field cleavers, beaver cleavers and staple-type cleavers.

 

Operation

 

A notable characteristic of a mechanical cleaver is its long leaf spring. Typically. the fiber is held in position on the spring by a retainer while a blade is brought into contact with the fiber to scratch (score) the fiber. The technician then bends the leaf spring, causing the fiber to break along the score line. A skilled technician can achieve a cleave angle within 2 degrees of accuracy.

 

Applications

 

• Mechanical Splices

• Mechanical Connectors

• Multimode Networks

• Premise and Campus Installations

• Local Datacom Multimode Networks

• Other multimode applications not subject to tight loss budgets

 

Advantages

 

• Cost – Affordable enough to put one in every tool box. Prices range from $100 to $200.

• Low Maintenance – Simple mechanical design

 

Disadvantages

 

• Less Accurate – Provides less precision and repeatability when compared to a precision cleaver. Not suitable for preparing fiber for fusion splicing.

• Multimode Only – Not suitable for cleaving single mode fiber.

 

Summary

 

If you are required to do fusion splicing, there is no question about it – you need a precision cleaver. If you are doing mechanical splicing only, you can likely get by with a lower cost mechanical cleaver.

 

Be aware that a precision cleaver can perform both types of cleaving, allowing you to minimize signal loss in both single mode and multimode networks. Although purchasing a precision cleaver involves a higher upfront cost, it may prove to be the best value in the long term.

 

Cleaver Specifications (Typical)

 

Precision Cleavers – Models are available for use with 250-µm to 900-µm coated fibers. V-groove alignment and adjustable cleave lengths can provide consistent cleave angles of 90 Degrees +/- 0.5 Degrees. Precision cleavers are available with diamond blades, with 16 or more blade positions that provide up to 3,000 cleaves per position. Precision cleavers can be purchased with fixtures that enable the cleaving of ribbon fibers and can accommodate 2 to 24 fibers.

 

Mechanical Cleavers – Models are available for use with 80µm to 200µm fibers or 900µm buffer or 250µm coated fiber. Mechanical cleavers provide cleave lengths of 2 to 20mm. These cleavers are available with ceramic blades that offer 1,000 cleaves or more, or carbide blades that can provide 5,000 cleaves or more. Mechanical cleavers typically include a graduated scale to indicate various cleave lengths.