Danger from damaged fiber optic cable?

Click For Summary

Discussion Overview

The discussion revolves around the safety concerns related to damaged fiber optic cables, particularly in the context of potential eye damage from laser light. Participants explore the implications of fiber optic cable integrity, the nature of the laser light used in FTTH systems, and the effects of damage on light emission.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions whether the lasers in FTTH single mode cables are powerful enough to cause eye damage, referencing a warning label on their NTO box about the laser beam.
  • There is concern about the potential for a fiber optic cable to be damaged by pets, specifically whether such damage could allow light to escape and if that light would remain dangerous or become harmless.
  • Another participant cites an article suggesting that the risk of eye damage from looking into a broken optical fiber is very low, as broken surfaces tend to scatter light.
  • A later reply expresses agreement with the interpretation of the article, indicating that a crack in the cable would likely result in scattered light rather than a concentrated laser beam.

Areas of Agreement / Disagreement

Participants generally agree that the risk of eye damage from looking into a damaged fiber optic cable is low, but there is no consensus on the specifics of how damage affects light emission and safety.

Contextual Notes

Participants express uncertainty about the exact nature of light emission from damaged cables, including the effects of different types of damage (e.g., cracks vs. complete breaks) and the implications for safety.

csd
Messages
10
Reaction score
0
Hi all,
I was not sure where to post this, so feel free to move the thread if the forum is not the most appropriate.
I was reading about safety in fiber optics and the fact that one should not be staring into a fiber optic cable to avoid eye damage. That's pretty obvious, but it also raises a few questions.

Are the lasers in FTTH (fiber to the home) single mode cables powerful enough to cause eye damage? For example my NTO box uses an infrared laser beam and a sticker on its back says: "Class 1 laser device. Laser beam when opened. Do not stare into beam". I am not sure if it means that it's class one because the beam is not accessible under normal usage, or because the laser is not powerful enough.

What would happen if the fiber optic cable was damaged. For example my cat adores biting small cables. I have protected the fiber optic one. But in case the cat bit the cable, could it damage it in such a way that the connection still works but some of the light escapes through the sheath?
Would such a leak remain in laser form and be dangerous? Or would light be scattered in all directions and therefore become harmless?

Would things change if the cable was damaged by bending it too tightly?

thanks ;)
 
Last edited:
Engineering news on Phys.org
Thanks for the link, according to the article:
The odds of going blind by looking into the broken end of an optical fiber are virtually nil, since the broken surface tends to scatter the light coming through it.

My cable is not even broken in two. If anything it has a crack at some point. So I guess any leaking light would be scattered and not in laser form. Is this right?
 
I am not qualified to say - in any case my lay interpretation of the article is the same as yours, for whatever that is worth.
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 22 ·
Replies
22
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 25 ·
Replies
25
Views
4K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K