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> efficiently converts optical power to electrical power Damn, I thought it was just a copper pair going along the fibers. I hope they provide some thick safet
by BenoitP 3y ago
> efficiently converts optical power to electrical power
Damn, I thought it was just a copper pair going along the fibers. I hope they provide some thick safety glasses with that.
I don't know if it'd come out as laser light, but 600 mW puts it into class 4 (eyes are damaged at a few 100m distance):
https://www.lasersafetyfacts.com/resources/FAA---visible-laser-hazard-calcs-for-LSF-v02.png https://www.lasersafetyfacts.com/resources/FAA---visible-las...
- TheTxT 3y agoMaybe it can first check if something is on the other end before blasting full power
- v7n 3y agoSomething like what? An eye?
- Gare 3y agoSomething that responds to a protocol handshake?
- publicmail 3y agoI think most high power optics do this already, right?
- onionisafruit 3y agoSo a freemason
- moffkalast 3y agoblinks in IEEE
- mikewarot 3y agoIt does that, if I understand what I read about it a year ago.
- NavinF 3y agoYeah that's exactly how higher power (compared to 40km SFP modules) communication lasers work and why nobody wears laser goggles in a data center. Automatically turning the laser off when the other side stops responding is ancient tech
- ExoticPearTree 3y agoYou 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-1482f39eeb7fe2a2abc3631275f95e42-c https://qph.cf2.quoracdn.net/main-qimg-1482f39eeb7fe2a2abc36...). Anyway, common sense says you don't look with your unprotected eye through a fiber endpoint.
- onionisafruit 3y agoWhat 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.
- ttoinou 3y agoYeah it's provocatively funny
- onionisafruit 3y agoThanks. I must be awake too early because it didn’t occur to me the sign is a joke.
- afandian 3y agoI think part of the joke is that damage is instantaneous so if you’re not prepared you can’t take evasive action.
- 3y ago
- hotpotamus 3y agoAnd if infrared, you won't even see it, and even reflections can be damaging to the eyes in theory.
- kiicia 3y agogreen lasers are scaring the heck out of me, each one of them is pumped IR laser and each reflection causes green beam and IR beam to diverge more and more
- lexicality 3y agoLooking up the specs, the actual laser is 1.5W, the converted output power is 600mW. The chart you linked suggests that it'll start fires if you accidentally break the fibre.
- RCitronsBroker 3y agoI have several lasers in that category somewhere in the depths of the electronics stuff i accumulated from hoarding and reselling it for years, including a surplus fiber laser i auctioned myself into owning. They can certainly start fires under the right conditions, but that requires the fiber end to be polished VERY well, otherwise, the beam isn’t focused enough to deliver the needed energy, bundled up on one spot. Still way enough to make you blind before you notice tho, nothing to skimp on in any case.
- TheDudeMan 3y agoProbably the power would stop when the fault is detected.
- avsteele 3y ago800 nm (NIR) does present hazards. Most people can't se it until the intensity is very high, so you blink reflex doesn't protect you. Having said that, it is probably highly divergent out of the fiber (depends on type). There's no risk beyond a few cm. Don't stick the fiber it up against your eye though. To answer someone below its unlikely you could get burned except right at the fiber tip. You can stick your hand in a 1.5W beam as long as it isn't tightly focused.
- lightedman 3y ago"it is probably highly divergent out of the fiber" Those of us in the styropyro discord have found that to almost never be the case. WEAR EYE PROTECTION AT ALL TIMES.
- avsteele 3y agoWhat types of fibers are you talking about?
- lightedman 3y agoSingle-mode, multi-mode, etc. All fibers. Let's use my LASER marker at work as an example. Divergence in that fiber happens AFTER two things happen - first the photons need to leave the fiber,then they have to cross-over their 'hip' (where the collimated beam is tightest) THEN they diverge. That's how fiber LASER markers work. I'm the operator of them where I work (I do everything outside of SMT - x-rays, LASER marking, high-voltage testing, etc.) Every LASER coming out of that fiber hits focal point about 2 feet past the fiber, where it begins to diverge. Do not trust a LASER coming out of a fiber to be unfocused or not have enough power density to blind you. Period.
- avsteele 3y agoThat's fine safety guidance but on the facts this is not correct. For single and multimode fibers if it has a smaller focal spot some distance the fiber than at its tip you are talking about an assembly that includes the fiber plus an optic. This is unambiguously true for single mode fibers. Multi mode one will diverge less I could see there being some exception for a strange fiber which has a multi-emitter output, was nanostructured, tapered, etc..
- zrail 3y ago> a copper pair going along the fibers I learned the other day that this is actually a thing one can buy. Direct bury hybrid fiber copper, up to looked like 2 OS2 strands and 2 12awg copper conductors. It's fantastically expensive but might be worth it for certain applications, like cameras that are beyond PoE distance limits and also don't have power available.
- xoa 3y agoI wish this was a broadly supported and mass manufactured standard and the industry had gone more that way ages ago. Optical for data and still have a couple plain strands of copper (no need for shielding, twisted pairs etc) for power. There isn't any particular reason it should be fantastically expensive beyond lack of mass manufacturing and standards. Ah well.
- zrail 3y agoHonestly it probably only helps installation costs, and not by much. There are no code issues with running standard direct bury copper in the same trench as direct bury fiber, nor are there any code issues (iirc, I am not an electrician) with running them in the same conduit even. Plain direct bury OS2 and 12/2 or 12/3 copper is dirt cheap and the fancy cable they use for generators that has 12/3 plus additional current sense conductors isn't that much more expensive.
- Moto7451 3y agoWith 12AWG, depending on the cable type and rating, you can bring 20-30A (90C rated) of power to go with your fiber in the same pull. The cable might be expensive but I’m sure the use case is great for when you don’t want to spend $10,000 on bringing a service trunk and meter to where your network equipment is being installed.
- dylan604 3y agoSounds perfect for long runs requiring repeaters/boosters or whatever kind of inline equipment that could be necessary
- amluto 3y agoThat chart is for collimated lasers. There is nothing especially inherently dangerous about laser light, and 1.5W or so of light is common (your average household ceiling light is in that ballpark). A fiber break is a point source (more dangerous especially at very close range) and is a bit focused, but it’s not going to burn holes in your skin or cornea at any appreciable distance. If it’s a wavelength that penetrates to the retina, then maybe the fact that it’s a point source will make it more dangerous if it’s in focus.
- hinkley 3y agoThis is 35% efficient. 1.5W in and .54W out. That’s not efficient in my book.
- NavinF 3y agoThat's a matter of perspective. Are you comparing to copper or to other electrically isolated power transmission tech? A typical LED is 40% efficient and a typical solar panel is ~20% efficient. A typical Qi charger is ~50% efficient. I stopped using cables for portable devices a few years ago and use magsafe instead which is supposedly has 75% efficiency due to perfect alignment of the coils, but that's still nowhere close to the ~100% you get from copper cables.
- hinkley 3y agoI suppose if you're just running one of these, we are talking about 8 KWH per year wasted. There are devices in my home burning more standby power than that. If you're running a whole cabinet of these then it's not the greatest.