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Comment by ExoticPearTree | Hacker News Reader

You know, in some places there are warning signs that read: Do not look into laser with remaining eye (https://qph.cf2.quoracdn.net/main-qimg-1482f39eeb7fe2a2abc36...).

Anyway, common sense says you don't look with your unprotected eye through a fiber endpoint.

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What does looking at a laser have to do with being safe from a class 4 laser? You could be two rooms over and be blinded by it if there are specular surfaces (which there usually are).

You probably still shouldn't look into the laser with your remaining eye, though.

Most fiber/transceivers you commonly find in a datacenter won’t cause eye damage:

https://www.nanog.org/news-stories/nanog-tv/top-talks/tutori...

(slides 79-84)

This is definitely not a most common transceiver, which is the point of all the commentary.

I'd refuse to buy this thing unless there was some national security reason for doing so, and then there would have to be interlocks on the room to de-energize it when anyone entered.

Disclaimer: I recommend you don't look at lasers as a standard practice.

For more context, an SFP+ 10G LR 10km module is Class 1 (completely harmless during normal use).

Same with a 100G LR4 type module.

The ZR type modules that run 100+km are also Class 1.

Pretty much any optical module you plug into a router or a switch is Class 1.

Where you should definitely be cautious is:

- Around optical amplifiers, where things can get into Class 2 and 3.

- DWDM setups where each module may be a Class 1, but the sum of their light adds up into something harmful.

They are class-1 only because the system is designed to not have any light visible during normal operation. Interlocks can be the only difference between a class-1 and a class-4 laser.

You dont have to look at the laser at all, scattered beam can be dangerous as well. Note: class 4 lasers have no upper bound, they are just hazardous.

Have these ever been weaponised?

You betcha. I remember in the late 90s an anti sniper technology that could detect lenses at long distances and fire a laser at them.

The idea was to mess up scope optics, but human heads have lenses too. It was not Geneva Conventions friendly.

Wow that’s pretty amazing. Wonder why I’ve never seen it in a film or tv show.

I’d love to read more about this. Especially the part about the Geneva Convention.

I’m guessing it was the Protocol on Blinding Laser Weapons.

https://en.m.wikipedia.org/wiki/Protocol_on_Blinding_Laser_W...

Experimentally, sure: https://en.wikipedia.org/wiki/Laser_weapon?wprov=sfla1

Big pewpews require big power and it's not super practical yet

US Navy has a few deployed and in use

https://en.wikipedia.org/wiki/AN/SEQ-3_Laser_Weapon_System

Wikipedia says that one is just one unit on one ship (moved to another ship). Has it seen more widespread production since then?

The end of the article mentions another system, HELIOS, but didn't have much more information, and that was only two units, I think?

I believe you, just wondering how widespread these are relative to traditional projectile weapons.

I think they are still in the testing phase but they are being deployed. The Marines do this all the time with all kinds of tech.

I've read that the main reason they like it is more about the incredible long range optics and not the laser, tbh.

It's against the Geneva Convention to use blinding weapons.

Sadly it's not against it to use killing weapons.

Has the Geneva convention ever stopped anyone? They can only arrest you if you lose the war, and people don't tend to plan for that.

General rule of thumb: if it's been banned, it's useless for the signatories. Ex: chemical weapons, but also biological weapons, land mines, and cluster munitions. Note that land mines and cluster munitions are still actively being used, especially in Ukraine, and the countries that signed onto the ban largely got rid of those systems well before the ban was signed.

It has. That's why countries don't have real chemical weapons anymore. They are easy to make (for an industrialized country), but they don't provide any real advantage when both sides in a war have access to them. They just increase misery for everyone involved.

Blinding laser weapons are in the same category.

That's not really the Geneva convention though, chemicals weapons are just not effective for any actual warfare (aside from committing atrocities).

I'm sorry but that is totally incorrect. Being able to clear out a building without damaging its capacity to provide cover is enormously useful.

Chemical weapons are incredibly useful, just awful.

The argument I've seen against their usefulness is that they only work against static militaries that don't have NBC training, and a modern military can already defeat threats like that without paying the political cost of using them.

https://acoup.blog/2020/03/20/collections-why-dont-we-use-ch...

> Chemical weapons are incredibly useful

They're not. They're effective against an unprepared adversary. Any real military will have anti-chemical-weapons tactics and protection.

So this happens: you douse a building with a gas, and then walk inside and get shot by defenders in gas masks. And by the way, you also will have to wear a gas mask yourself.

https://en.wikipedia.org/wiki/Dazzler_%28weapon%29?wprov=sfl...

They're "intended" to cause only temporary blindness

The application would be more civil than war-alike, if it existed.

That's even harder to prosecute, pretty much no one is starting a war over what rulers are doing to their own citizens.

Still need a major supplier both the laser emitters and esp. the optics. The weapons will be a lot more expensive compared to conventional weapons, or any anti-riot weaponry.

Aside the sci-fi vibe, I could imagine James Bond esque - still quite hard to use, has to aim for the eyes, scatter can cause collateral damage, doesn't work in fog, rain, etc.

They are called direct energy weapons, more like a sci-fi, though.

It'd be a rather short range weapon, that's not easy to aim, require a line-of-sight, can't penetrate armor... or goggles, or fog/dust.

I’m pretty sure high powered lasers penetrate goggles by just vaporizing them.

True but how would you deploy high powered ones and keep line of sight?

Use an X-Ray laser, as Larry Niven liked to use as a MacGuffin in a few of his stories

“Common sense”?

Never had one of those toys…

https://images.app.goo.gl/nFwVrEe26vkxxJWLA

I find these tremendously helpful https://i.etsystatic.com/13650636/r/il/617182/2062686717/il_... as popularized by AvE

What does that mean? I read it as people who have already lost an eye shouldn’t risk their only remaining eye, but I think I’m missing something.

It's tongue-in-cheek, implying that many people working with the stuff already lost an eye to it.

It's part joke and part telling people "hey, this stuff is really dangerous, take it seriously or you'll lose an eye, or both". I don't think I've seen a single lab with high-powered lasers that didn't have a variant of this sign.

A similar popular sign for chemical labs is "Carol Never Wore Her Safety Goggles. Now She Doesn't Need Them", depicting a blind woman with sunglasses and a white cane. (https://knowyourmeme.com/memes/carols-safety-goggles)

I think part of the joke is that damage is instantaneous so if you’re not prepared you can’t take evasive action.

On top of this, we can't see 800 nm light. That's well into the Infrared band so "invisible lightsaber for your eyes" is an exaggeration, but helps visualize what you could be dealing with.

I think that sometimes when humor is added, in this way, it is to make you pause first.

At least in my mind when I encounter something oddly said/written my mind starts suggesting contexts and I can clearly "see" myself going blind by doing me like things.

It emphasizes that you will only notice there's something dangerous around after you are already blind.

It's a very well worded warning, that spread because it's effective. The official warning saying that you must take precautions even if you don't see anything wrong just doesn't work well.

Yeah it's provocatively funny

Thanks. I must be awake too early because it didn’t occur to me the sign is a joke.

The joke being is that's not a joke.

It's a quantum joke

"Danger: Not Only Will This Kill You, It Will Hurt The Whole Time You're Dying"

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