Used Fibers

Light Loss Along Length

I took the segments of wave guide that I had examined under microscope and exposed them to a green laser pointer with very little ambient light. The laser illuminated the wave guide and revealed the effects of surface damage. Areas with fissures, dust, or residue sparkled under the green light. This indicates significant light loss. Understanding light loss is key to the success of the tagger microscope.

Figure 1: The effect of many surface imperfections becomes obvious when looking at a length of illuminated light guide. (Previously processed light guide. MFR: Saint Gobain BCF-98)

Surface Imperfections

Details of the damage are visible in these pictures.

Figure 2: Detailed surface imperfections in previously processed light guide.
Figure 3: Surface imperfections in previously processed light guide.

Figure 2: In the upper right-hand third of the image are two parallel bands outlining a section of wave guide that seems brighter. This corresponds to the glue residue from the sticky labeling system. Other damage can also be seen.

Figure 3: Nicks, gouges, and residues coat the length of the fiber, causing light loss everywhere.

New Fibers

Clarity

Freshly cut light guide demonstrates remarkable clarity and minimal light loss. These images illustrate the smoothness of an undamaged surface.

Figure4: Light Guide recently cut from spool shows exceptional clarity under laser light.
Figure 5: Polished end of light guide away from light source, recently cut from spool. Long exposure reveals minimal light loss relative to end.
Figure 6: Top view of light guide recently cut from spool. Uniform brightness indicates few surface abnormalities.

Damage from Clamp

The pictures below all reveal a band of damage near the clamped end of the spooled light guide. This discovery is important: if a weak foam-lined clamp (chip-clip style) can cause this damage, then one must wonder about other potential mishandling. I have observed hook-and-loop ties used to store fiber bundles, fibers laid across tables, fibers laid over sandpaper (quickly moved when pointed out), and fibers rubbing against other fibers. I hypothesize that the sharp edges of the square guides are most prone to damage, but that all procedures for manipulating fibers are leaving marks. Pictures of the chip-clip and the hook-and-loop fasteners to come.

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Other Surface Imperfections

Figure 10: Minimal surface imperfections visible near end of new light guide.
Figure 11:‎ Imperfections along edge in new light guide.
Figure 12:‎ Two sides of the wave guide are visible and minimal light loss is observed. Bright region due to laser angle.

Laser Images

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