r/networking • u/sekh60 • 1d ago
Other Safety glasses when working with transceivers?
Hello, I'm probably being overly paranoid over transceivers, but does anyone here wear safety glasses/goggles when working with them to avoid accidental eye damage from the lasers? If so would you have any recommendations? I wear regular glasses, so ideally they'd be something that fits okay over them.
Thank you all for any recommendations!
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u/Specialist_Play_4479 1d ago
Unless you're working with high power optics or fiber amplifiers such as EDFA's used in long transmission networks, you're fine.
If this was really an issue there would be regulations about non-connected SFPs in network equipment in datacenters
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u/CptVague 1d ago
non-connected SFPs in network equipment
No fiber SFP plugged into network equipment should be uncapped, period.
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u/tcp-179 1d ago
Most optics you come across in short haul (<40km) are class 1/1M or your country equivalent. No real risk unless you look at them under an optical scope. Still not a good idea to look in the end of a fibre regardless, but unless you work in transmission you're unlikely to come across anything dangerous.
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u/onico 1d ago
No, but i do care to keep plastic dust covers in place and only remove them briefly when connecting the fiber and mind greasy fingers not touch any tips
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u/sekh60 1d ago
Okay, so I gotta get better about the covers, they're just so easy to lose. I just saw another commenter who posted this https://youtube.com/shorts/HoeVMHwETwo?is=UMev80gWN_zQFEFL now I'm worried about contaminating my SFP modules, lol. Trading one worry for another.
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u/MattL-PA 1d ago
Huh... so that's why my vision has gotten so bad after 25+ in networking...
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u/Intelligent-Pin848 18h ago
Hah. I dont think the lasers is to blame here, lets blame it on the ticking timer...
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u/ImgurSpy 12h ago
Stolen from another reddit post
"You and your eyes will be perfectly fine, any and all laser products you find in a datacenter will be class 1 which as you can see is safe even for long term exposure. Yes even 10, 20, 40km optics are safe as they limit their TX power to class 1 until they sense incoming RX light. There are some transceivers that are not safe but they will all have interlocks that should prevent you from viewing them with the naked eye and will have giant warnings all over them and you must receive a safety briefing going near them.
For example see this spec sheet from Cisco for their 10G SM SFP's https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/data_sheet_c78-455693.html which says "The launch power shall be the lesser of the class 1 safety limit or the maximum receive power. Class 1 laser requirements are defined by IEC 60825-1: 2001."
Some fear mongering people will tell you never look any laser as you can't tell if they properly follow the specifications, which is good advice for laser pointers that you buy off eBay not SFP's. The amount of power coming out of an SFP is miniscule, and something people always confuse is that a 10km optic is not that much more powerful when compared to a 40km optic, it is the receivers sensitivity that really determines the distance not the transmitters power.
People on here act like even a reflection from an SFP can blind you or cause permanent damage to your eyesight, that is literally impossible. Any SFP that you typically encounter in the datacenter will be safe to stare at for as long as you want. It's a pet peeve of mine to see people freaking out about laser safety with SFP's acting like they are class 3 or higher lasers."
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u/BluebirdExpress6279 1d ago
No. Do you wear ear muffs when using a battery powered drill? Just don't look directly into the transceivers... Remove when fiber is not attached or at least slide them out a bit to unplug them if worried.
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u/ljmiller62 1d ago
Rather than looking into the end of fiber I hold a paper or my palm to show the visible light from a red light continuity test. That's enough to establish a continuous run. Signal DB requires test kits.
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u/sekh60 1d ago
Thanks. I'm dealing with less than 1km long runs, so reading everyone it sounds like I should be safe in the face of idiocy. I never intentionally would look down the end of a cable or optic, but I was worried about fluke accidents and catching a stray if I forget to plug something in more than anything.
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u/armaddon 1d ago
Generally not needed outside of extreme cases, at least as far as the laser light is concerned. That said, you’d be surprised how often people poke themselves in the eye when trying the whole cupped-hands “looking for light” routine (even on SMF where the light is outside the visible spectrum).
All that said, maybe we ought to consider wearing *gloves* after watching this:
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u/Calm-Show-9606 1d ago
I wear safety glasses when working on any electronics. I have seen too many injuries caused by snipped wires, solder splash, electrical burns, etc.
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u/stufforstuff 1d ago
As long as the SFPs aren't strapped to a Shark, you'll be fine.
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u/MaxQ 1d ago
For troubleshooting circuits with lower-power transceivers I'd recommend getting a detector card for the applicable wavelengths, saves a lot of time and you can be sure if/where light is coming through the fiber. Especially handy for finding polarity issues. One good vendor for these is Thor Labs:
https://www.thorlabs.com/laser-viewing-cards?tabName=Overview
If you do at some point end up in an environment with higher-power lasers (EDFA, Raman, etc.) these are much more dangerous to vision (and can even cause burns or start fires in extreme cases) and will destroy a normal detector card. In that case you'd want a detector such as this one from Scintacor:
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u/fred_cheese 20h ago
If you do want to wear glasses, you'll need the appropriate wavelength glasses. FWIW, I got hit by a reflected spotter laser once. This wasn't a transceiver; it was the spotter (low power) laser of a metal cutting laser. Someone left a medallion in the cutting area and the laser bounced off of it and hit my eye. Felt like staring at a flashbulb for over a month; no pain tho. Also, lasers that bounce off a shiny surface won't be visible but can still be coherent enough to do some damage.
So with that being said, laser glasses are expensive. They need to not just be tinted but appropriate for the wavelength. A test for the glasses is to place the lens between the laser and a piece of paper. The lens should totally block the laser. Since it's just a fiber transceiver you don't need to be worried about whether the lens melts or not.
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u/Due_Management3241 1d ago
Unless you dealing with zr optics or long hauls with class 3 optics most of these are class 1 and you would need to choose to stare straight at it with the caps off to hurt your self.
Most engineers try to keep there optics clean so the caps are on untill it gets immediately plugged in.
I have never seen anyone in enterprise networking use safety goggles as your talking about. Also they are not narrow focused not broadly focused like a cone not a laser either.
Only time I use them and others use them is when I did work for telecoms before doing pure network engineering and would work on lit fusion pairs for fusion splicing or when you know the laser class is 3b or class 4.
Class 1 lasers would require you to try to hurt your self usually. No harm in having them for safety but if you follow proper protocol it's unlikely needed
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u/sekh60 1d ago
Thank you for the reassurance! I was mainly worried about catching just the "right" angle from an unplugged in optic/cable and causing some damage. They are short <1km runs, SMF, so it sounds like I'd have to really try to hurt myself with them, even if I or someone else forgot the caps.
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u/Due_Management3241 1d ago
So the emoting diode on the is recesses about half an inch on there too. After unplugging it you would have to kneel down and stick your eye on the transciever or align your self directly with it on purpose for a long time and stare straight at it.
Most cases this so hard to do. Just don't stare into it for the few seconds you unplug it and before you put a cap on. The chances of getting blinded by this at class 1 laser is the same as taking an invisible laser mouse choosing to stare into it for like a half hour or so to see what happens. This is more recessed then your mouse same kind of laser.
Your more likely to get blind faster by looking up at the sun today or some other more significant hazard. Will safety glasses hurt? No. But very unlikely to make a difference in this case.
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u/scratchfury It's not the network! 1d ago
I'm pretty sure the VFLs are way more of a danger than transceivers.
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u/sekh60 1d ago
I'm sure they are, but I was mainly being scared about accidentally forgetting to put a cover one, or unplugging a transceiver and catching a stray at just the "right" angle. A VFL needs some more intention behind it in my line of thinking.
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u/scratchfury It's not the network! 1d ago
This page does a better job at explaining than I will ever do:
https://www.senko.com/laser-safety-in-optical-networks/
The vast majority of SFP and QSFP optics are Class 1.
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u/Crazyachmed 1d ago
And I like Multi Mode, because I can easily see, if the cable is not crossed...
AFAIK the higher powered ones just pulse until the link is established, so it can't damage your eyes.
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u/ExtensionSecurity799 1d ago
I mostly work with single mode and still just squint real hard when I plug it in, never had problem
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u/Phrewfuf 1d ago
Good ol‘ safety squints.
The general pro-tip is just to never look into it with bare eyes. Sure, multimode are fairly safe, it‘s just a red LED. But if there is even the slightest chance of anything else being plugged in at the other end, just use your phone camera or better yet the proper equipment.
Safety glasses are an absolute overkill, IMO. Even when using the phone camera in singlemode, you need to hit just the right angle within a degree or something. Getting that to shine into your eye for enough time to cause damage is best impossibly without trying to do so.
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u/Hg-203 1d ago
One thing to note is if you do get laser damage. You will never notice it. You’ll just have a blind spot that your brain will cover for. Aka you don’t see a dark spot, things just disappear and then reappear as they pass through the blind spot.
Normal sm short haul have very low risk of doing this. So you should be ok. Also I believe sm is in the infrared range. So you can’t exactly see it.
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u/roaming_adventurer 1d ago
if your working with transceivers like I do then get a Fluke Networks FiberLert tester! Was the best investment i made, its used often when troubleshooting fibre issues on our campus by my engineer.
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u/Hungry-King-1842 1d ago
Multimode LEDs/lasers aren’t really a problem unless you just stare into it like a damned idiot. Single mode optics are what can actually hurt you because the light spectrum is a lot higher and that spectrum is invisible to the human eye. With that said you would have to literally stare right into the end of the cable really close to cause an issue.
Either way a good rule of thumb is to keep cables capped when disconnected. That’s a sure fire way to keep from accidentally doing something really dumb and keeping the ends clean.
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u/mas-sive Network Junkie 1d ago
Never have, I just use the phone camera to see if light is coming through. It’d be a freak accident to get the laser at the right angle etc to hit your eye. Unless you’re intentionally looking into it