Clement CavadoreJan 12, 2024

Why you should NEVER look directly an optic fiber panel: you dont know the power of the signal 🔥

Source: https://www.reddit.com/r/FiberOptics/comments/167jjlh/is_the_signal_too_strong/

Show threadLRJan 13, 2024

@acontios wow that's an alien toot. what the hell am i even looking at %) what is that pen. what is a fiber optics panel

feel free to mansplain, i implore you

Show threadNick TaylorJan 13, 2024
@lritter The pen is either an optical transmission module or the end of an optical fibre connected to one. In normal operation, electrical signals get converted to pulses of near infra-red light (usually 1310 nm or 1550 nm) and that white bit at the right would be clamped against a matching bit on an optical fibre, which will carry the signal for (wild guess based on the power here) a few hundred miles. At the far end the much-attenuated light will get converted back to electrical signals.
Show threadNick TaylorJan 13, 2024

@lritter The light coming out of that white bit has to be quite intense to be detectable after that much distance, so it's intense enough to make black electrical tape smoke.

You do not want this to happen to your eyes.

Show threadNick Taylor
@lritter A fibre-optics panel is a bunch of these mounted next to each other, into which you plug fibres. Some of these fibres will be going across the room, and have low-power transmitters on them. Some will be going a long way. If those long-distance fibres have been unplugged, the connector they should be plugged into can be emitting literally eye-searing invisible radiation.
Jan 13, 2024 at 1:03pmWeb
Show threadLRJan 13, 2024
@tienelle ahhh! now i get it. so this signal would likely be transmittable over a very long distance since its power is so high, hence even under attenuation by inverse squared distance (through a reflective fiber cable though), it would be unlikely to degrade below ambient noise levels
Show threadAyron Jan 13, 2024
@lritter @tienelle It's not only the optical power, it's the density. As this is a SC/APC-plug, the fibre-core is 9µm thick. The whole power is so concentrated, that it burns that piece of duct tape (or your skin and eyes)
Show threadLRJan 13, 2024
@ayron @tienelle ah. you're saying that the shape of the cable bundles the light almost like an array of lasers.
Show threadAyron Jan 13, 2024
@lritter that's the point. The light output of an fibre optic transmitter is lower than that of a flash-light bulb. Looking into the filament of a 100W incandescent light bulb hurts in the eyes. Looking into a 58W fluorescent tube is no problem, although the fluorescent tube outputs about 4 times more light.
Show threadNick TaylorJan 13, 2024
@lritter @ayron Very like; the light spreads out a bit, but over a sort of 10° cone, so it stays hazardous for quite a distance from the connector.
Show threadNick TaylorJan 13, 2024
@lritter Correct. For single-mode fibres (which is what @ayron thinks these are and I see no reason to doubt them) the main cause of attenuation is absorption of light by the fibre: optical fibre is very nearly transparent but over long distances that "very nearly" adds up to "quite dark really".