Difference between revisions of "Laser Images"

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=Used Fibers=
 
=Used Fibers=
 
==Light Loss Along Length==
 
==Light Loss Along Length==
[[ File:Cropped Used WG Loss LengthwiseDSC 0169.JPG |thumb|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)]]
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I took the segments of wave guide that I had examined under microscope and exposed them to a green laser pointer in a dark room.  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.
 +
 
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[[ File:Cropped Used WG Loss LengthwiseDSC 0169.JPG |thumb|center|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==
 
==Surface Imperfections==
[[File:Cropped Used Surface imperfections 1 DSC 0200 (2).JPG Detailed surface imperfections in previously processed light guide. (MFR: Saint Gobain BCF-98)]]
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Details of the damage are visible in these pictures. 
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<gallery>
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File:Cropped Used Surface imperfections 1 DSC 0200 (2).JPG |Figure 2: Detailed surface imperfections in previously processed light guide.
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File:Cropped Used surface imperfect 2 DSC 0201.JPG |Figure 3: Surface imperfections in previously processed light guide.
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</gallery>
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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.
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Figure 3: Nicks, gouges, and residues coat the length of the fiber, causing light loss everywhere.
  
 
=New Fibers=
 
=New Fibers=
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==Clarity==
 
==Clarity==
 
Freshly cut light guide demonstrates remarkable clarity and minimal light loss.  These images illustrate the smoothness of an undamaged surface.
 
Freshly cut light guide demonstrates remarkable clarity and minimal light loss.  These images illustrate the smoothness of an undamaged surface.
[[File:Exceptionally Clear New LG 0005.JPG|thumb|left|Figure 1: Light Guide recently cut from spool shows exceptional clarity under laser light. (MFR Saint Gobain BCF-98)]]
 
  
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<gallery>
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File:Exceptionally Clear New LG 0005.JPG|Figure4: Light Guide recently cut from spool shows exceptional clarity under laser light.
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File:Open Shutter LG End DSC 0020.JPG|Figure 5: Polished end of light guide away from light source, recently cut from spool. Long exposure reveals minimal light loss relative to end.
  
[[File:Open Shutter LG End DSC 0020.JPG|thumb|Figure 3: Polished end of light guide away from light source, recently cut from spool. Long exposure reveals minimal light loss relative to end. (MFR Saint Gobain BCF-98)]]
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File:Bright Clear Nearly Perfect DSC 0019.JPG|Figure 6: Top view of light guide recently cut from spool. Uniform brightness indicates few surface abnormalities.  
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</gallery>
  
[[File:Bright Clear Nearly Perfect DSC 0019.JPG|thumb|center|Figure 2: Top view of light guide recently cut from spool. Uniform brightness indicates few surface abnormalities. (MFR Saint Gobain BCF-98)]]
 
  
 
==Damage from Clamp==
 
==Damage from Clamp==
[[File: Fast Shutter Clamp Damage DSC 0368.JPG|thumb|]]
 
  
[[File:Cropped DSC 0059.JPG|thumb|]]
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The pictures below all reveal a band of damage near the clamped end of the spooled light guide.  The damage goes all the way around the fiber and is only found at this point.  I used extreme care when cutting the fiber and transporting it, and I do not believe these marks are from me.  The implication of these images 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.  all of these scenarios are equally or more abrasive than the chip clip.  I hypothesize that the materials coming into direct contact with the fibers are leaving the most damage,  but that many, if not all, procedures for manipulating fibers are leaving marks.  Pictures of the chip-clip and the hook-and-loop fasteners to come.
  
[[File:Cropped detail clamp damage DSC 0061.JPG|thumb|]]
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<gallery>
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File: Fast Shutter Clamp Damage DSC 0368.JPG|Figure 7 Damage to new light guide appears as a band around the end that was clamped during storage. 
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File:Cropped DSC 0059.JPG|Figure 8 Close up of damage near clamping site.
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File:Cropped detail clamp damage DSC 0061.JPG|Figure 9 Lower intensity laser allows the most severe scratches to be highlighted.
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</gallery>
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In Figure 7, I shined a laser through the new light guide and used a paper bowl to block ambient light from the laser.  To the left of the bowl, one sees bright spots on an otherwise dimly lit fiber.  This corresponds to the position of the clamp.
 +
 
 +
Examining Figure 8 reveals several marks along the right half of the fiber.  The leftmost striation is the most well-defined, and beyond that the fiber does not spill light.  I hypothesize that the clip may have been re-positioned, leaving other scratches, but the leftmost band was the farthest down the fiber that the clip was placed. Some of the poorly defined light loss from the right might simply be due to the position of the laser.
 +
 
 +
Figure 9 offers an alternate view with less ambient light.
 +
 
 +
It should be noted that the amount of light in the images varied because the laser intensity varied greatly.  It would gradually get dimmer with time, until I removed the batteries and then put them back in.  Interrupting contact with the batteries made the laser bright again.
  
 
==Other Surface Imperfections==
 
==Other Surface Imperfections==
  
[[File:Bright surface imperfections Cropped DSC 0030.JPG|thumb| ‎ Minimal surface imperfections visible near end of new light guide.]]
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The photos included below were taken after handling the segment for a few hours.
 +
 
 +
After taking many pictures, I started to notice more bright spots along the fibers.  While I had taken care not to bang or scratch the fibers, I could not prevent the accumulation of dust.  It is even possible that, despite my gentle and gloved handling, the fibers sustained surface damage.  No events occurred that seemed harmful to me at the time, but the light loss is indicative of the fibers' general fragility.
 +
 
 +
In particular, Figure 11 reveals specks of light loss along the edge.  In this case, I believe I observed cloth fibers adhering due to static.  However, I assume that the edges of the fibers are also the most prone to damage because they have the least amount of material.
 +
 
 +
<gallery>
 +
File:Bright surface imperfections Cropped DSC 0030.JPG|Figure 10: Minimal surface imperfections visible near end of new light guide.
  
[[ File:Cropped lower light edge imperfections DSC 0054.JPG|thumb| ‎ Imperfections along edge in new light guide.]]
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File:Cropped lower light edge imperfections DSC 0054.JPG|Figure 11:‎ Imperfections along edge in new light guide.
  
[[ File:Cropped 2 surface some loss DSC 0056.JPG|thumb| ‎ Two sides of the wave guide are visible and minimal light loss is observed. Bright region due to laser angle.]]
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</gallery>

Latest revision as of 03:31, 29 January 2016

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 in a dark room. 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: 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.


Damage from Clamp

The pictures below all reveal a band of damage near the clamped end of the spooled light guide. The damage goes all the way around the fiber and is only found at this point. I used extreme care when cutting the fiber and transporting it, and I do not believe these marks are from me. The implication of these images 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. all of these scenarios are equally or more abrasive than the chip clip. I hypothesize that the materials coming into direct contact with the fibers are leaving the most damage, but that many, if not all, procedures for manipulating fibers are leaving marks. Pictures of the chip-clip and the hook-and-loop fasteners to come.

In Figure 7, I shined a laser through the new light guide and used a paper bowl to block ambient light from the laser. To the left of the bowl, one sees bright spots on an otherwise dimly lit fiber. This corresponds to the position of the clamp.

Examining Figure 8 reveals several marks along the right half of the fiber. The leftmost striation is the most well-defined, and beyond that the fiber does not spill light. I hypothesize that the clip may have been re-positioned, leaving other scratches, but the leftmost band was the farthest down the fiber that the clip was placed. Some of the poorly defined light loss from the right might simply be due to the position of the laser.

Figure 9 offers an alternate view with less ambient light.

It should be noted that the amount of light in the images varied because the laser intensity varied greatly. It would gradually get dimmer with time, until I removed the batteries and then put them back in. Interrupting contact with the batteries made the laser bright again.

Other Surface Imperfections

The photos included below were taken after handling the segment for a few hours.

After taking many pictures, I started to notice more bright spots along the fibers. While I had taken care not to bang or scratch the fibers, I could not prevent the accumulation of dust. It is even possible that, despite my gentle and gloved handling, the fibers sustained surface damage. No events occurred that seemed harmful to me at the time, but the light loss is indicative of the fibers' general fragility.

In particular, Figure 11 reveals specks of light loss along the edge. In this case, I believe I observed cloth fibers adhering due to static. However, I assume that the edges of the fibers are also the most prone to damage because they have the least amount of material.