Chapter 5 Theory Of Cleaving; Specialty Fiber Cleaving Processes - THORLABS vytran LDC450B User Manual

LDC450B Large Diameter Cleaver
Theory of Cleaving
Chapter 5
The LDC450B automated fiber cleaver is designed for cleaving optical fibers with claddings from Ø200 µm up to
Ø1.25 mm. It is possible to cleave smaller fibers as well, but the smaller fibers are more difficult to position correctly
in the v-grooves. For this reason, we recommend the LDC401 and LDC401A fiber cleavers to people wishing to
cleave small-diameter fiber. Both of those models are equipped with a vacuum which sucks the fibers into the v-
grooves during loading.
To produce a flat cleave, the LDC450B uses a "tension-and-scribe" method, whereby an axial tension is first applied
to the fiber followed by an automated Scribe Process utilizing a diamond Cleave Blade.
Figure 8 Maximum stress is in the direction of the fiber axis, and the cleave is perpendicular to the
5.1.

Specialty Fiber Cleaving Processes

Two additional process capabilities are available on the LDC450B. These processes are primarily utilized for
cleaving specialty fibers such as microstructured fiber, highly stressed fibers (MM and PM), or capillary tubing. The
specialty fiber processes are used to produce flat cleaves and improve end face quality but require the execution
of additional steps.
1. Subcritical Process
The "Subcritical Process" applies a tension that is lower than required for a "standard" cleave. The blade
then scribes the fiber, and the tension is slowly (and incrementally) increased to propagate the scribe and
produce the cleave.
2. Micrometer Backstop
The flat surface of the micrometer end acts as a backstop for the fiber during the Cleave Process. When
using the Micrometer Backstop, it is possible to reduce the tension applied to the fiber.
Both of these processes will be described in greater detail in the next chapter.
Rev A, July 28, 2020
axis of the fiber
Chapter 5: Theory of Cleaving
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