How Does LIGHT Carry Data? - Fiber Optics Explained
ฝัง
- เผยแพร่เมื่อ 15 มิ.ย. 2024
- The first 200 people who head to brilliant.org/techquickie/ will get 20% off their annual premium subscription of Brilliant.
How do fiber-optic communications work?
LTT Merch Store: www.lttstore.com
Follow: / linustech
Leave a reply with your requests for future episodes, or tweet them here: / jmart604 - วิทยาศาสตร์และเทคโนโลยี
![เกิดใหม่ทั้งทีก็เป็นสไลม์ไปซะแล้ว ซีซั่น 3 - ตอนที่ 59 [ซับไทย]](http://i.ytimg.com/vi/GmW4a8prWUQ/mqdefault.jpg)
This is actually how fiber optics carry light rather than how light carry data.
true
Wait a minute... Your right!
yeah that sucks
It's ones and zeroes, just like conventional copper wires. Instead of elecricity going on and off, it's light going on and off :)
information is on and off combined with time multiplied by 1000 000 'sss
I tried absorbing data directly through Light mode and now my Retinas are scorched.
#NoFilter
You need to RMA your retinas. Don't tell Asus how you scorched them. Say you don't know how it happened otherwise they may deny the RMA
This is why everyone wants Dark Mode.
Learn from trump only during the solar eclipse!
*node
The human ability to absorb data using light... also known as "reading".
"minecraft redstone doesn't relate to reality at all" well now I have an objection
I was looking for this comment, wasn't disappointed
First year of my computer science degree we learnt about logic gates. That's literally redstone. Fun experiment for you, go on minecraft and make a NAND gate. This is a gate which has 2 inputs and 1 output. The output should always be ON unless BOTH of the inputs are on in which case the output should be off. The cool thing about NAND gates is that you can use them to make all other logic gates. Try to make the following gates out of just NAND gates (either building them manually or copy and paste using worldedit):
NOT - 1 input signal, output is on when input is off and off when input is on
AND - 2 inputs, output is only on when both inputs are on
OR - 2 inputs, output is on when either of the inputs are on
XOR - 2 inputs, output is on when either of the inputs are on BUT off if both inputs are on
You can keep building these up to create memory chips, processors and then a fully functioning computer! If you want to look further into it (outside of minecraft) then take a look a the website called nandtotetris.
All those Redstone creators back in 2014 well they work for NASA. What have you been doing.
@@Burtannia or just dissasemble NAND to NOT and AND
Like Redstone, if you spill a bucket of water on your redstone circuits you’re going to have a bad day.
But Linus, I thought you only stuck RGB lighting up there.
It finds the cancer faster
Backlog Buddies and Game Highlighter ???
@@anvthema1925 a joke about how rgb makes you preform faster
Wait... wait for 2021: RGB fiber optics
"White" light is RGB
I used to work on fiber optic equipment (wrote the software, but still had to know a good amount about the hardware). The way light carries data can be much more complicated than just flipping the light on and off. The transponder I worked on used 16QAM modulation sending the data in a combination of the amplitude and phase of the light, allowing for 4 bit symbols (any one reading from the fiber provides 4 bits). We transmitted at 200 gigabits per second (per slot within the ROADM network).
Same here still do, is amazing what you can multiplex it's basically the same principle just alot higher frequencies 194.1thz for example
Soon I hope we figure out how to match the visible and invisible spectrums with computer characters instead of just using one's and zeros
Why continue to communicate through Morse Code when we (the devices and connections they use) can say so much more in the same amount of time
Not a great comparison but think about how much better video chat is instead of just getting a page on your pager 📟
Now to factor in smell, touch, and taste ... ⚡📻📲📴🚫📶💡🚥
0:40 could you have possibly picked a creepier picture of a hallway?
and therefore one you would really want a torch
As an EE, I’m super impressed with how well this was explained!
E_ Engineer? What’s the other e?
@@jello9079 electrical
@@BichaelStevens Ah thanks
But didn't explain what the title said 😶
Eclectic entity?
As a high school physics teacher, I never knew about the repeaters and amplifiers. Instead, I always told my students about the wonders of eternally efficient fiber cables. Turns out air-resistance can't be neglected after all eh?
It's not air resistance, it's the dispersion of light at the molecular level. Repeaters/Amplifiers also need the power to operate, so copper wires are also needed to power all the amplifiers attached to the fiber cable. The big bundle of wires in that fat cable laid in the ocean contains amplifiers and copper cables to power those amplifiers as well.
@@Arslan2591 I was beginning to wonder how those amplifiers and repeaters got power and I also wonder what happens if 1 of them short out or something how would maintenance deal with it?
@@anything_idc_ Redundancy and failsafe methods are the first things that are in the minds of engineers who lay out such big projects. Copper wires are used to power up the amplifiers/repeaters on the way.
@@Arslan2591 nothing is fail safe. You can go as far as you can go to prevent anything from breaking but there is always the unknown. So it sounds like a simple process easier than running telephone poles
@@Arslan2591 but dispersion is an effect of air resistance. what do you think resistance means? if you place a mesh in front of a fan you are creating flow resistance and dispersing the air. same thing with electromagnetic waves. put any molecules in front of it and it creates resistance.
you and that physics teacher stun me. understanding this sh*t is not about learning facts or names it is about understanding concepts.
If you ever built a tree fort, .... secret message using a flash light... Kids today: U wot m8?!
Yeah I'm pretty good at building forts in Fortnite. The last the my enemies see is the flash from my muzzle.
Whats a tree?
Watch out! There's a boomer!
OK boomer
they don't even know what a real flash light looks like. all they ever see is the one behind their phones.
Why do I learn more in TH-cam than in my school.. ....?
because curriculum need hella time to adapt,while us,the youths,just use internet, neighborhood,and many more
This is actually taught in AP Physics II. We work out how to solve for when total internal refraction happens.
@@yohanwang6518 ?????
If you didn't learn total internal reflection in your school you're going to a shit school
Well that's good to hear..
Optical fibres that carry useful information over long distances are usually single-mode C-Band Telecom fibers. The "C-Band" refers to an optical window where Rayleigh scattering (the effect that makes the sky blue) and glass absorption meet to create minimal absorption of telecom wavelength (around 1550nm).
or 1310nm
@@bob-yo1tl 1310nm is the O-band, which is the first and least efficient of the telecom bands. They use noisier Pr amps instead of the Er amps used for the C-band.
@@AnAverageJho So it says that it shows 100% of total internal reflection but how are we able to see the the light travelling through it when the fibre is alone( like in some images on Google). If we are able to see the light travelling that means some light is escaping from inside it
@@AnAverageJho And yah one more thing that all the light rays in the optical fibre strikes on an angle greater than critical angle ? If yes how is it possible that no ray of light is scattering less than the critical angle? Is it because of geometric structure or the way we are striking the light
@@ulpnationll2953 There are so many things to cover with what you're saying that I have neither the time nor the crayons to explain it. Efficient fibers, called Ultra Low Loss Fibers, have 0.15 dB/km of loss only for one specific wavelength because of their core size compared to their cladding size (9um/125um) and because of the difference of refractive angle between the two.
If you don't couple light properly into the fiber, you get more losses because of total internal reflection, yes. Same if you bend the fiber too much. Fibers work because of the difference in refractive index between the core and cladding.
Fibers that work efficiently don't use visible light.
I am a IT consultants that became a network and fiber optic engineer and have been in the trade for many moons. Linus you should have mentioned the difference between single mode and multimode as their limitations are different. This is a very entertaining way to explain how light travels through a fiber but not necessarily how data travels or how its converted to light, we missed packets, frames, and labels, you also forgot to mention the vacuum in the fiber strands which allows for light to travel further. Nothing on attenuation or operation at 1310nm or 1550nm.
Next you glanced over wavelengths possibly due to time but Wave division multiplexing that grew into DWDM and its advances to go from 1Gbps and 10Gbps to 40, 100, 400Gbps are the reason global bandwidth has grown. Then 0 layer switching, it is what allows for light to be switched on demand without physical intervention. You could spend half an hour on that alone, Dont even start on ROADM's LOL. Also the chemical reaction discussed in helping light travel further only works with certain types of fiber strands, the rest need a physical regeneration point closer, converting light to electrical then back to light again, about every 80 or so kilometers. The physics of light energy at the output level disburses or degrades at this length, even in a vacuum or in a perfect reflective environment. So all major telecoms depending on the type of fiber whether Corning Leaf 0 dispersion have to plan their repeaters carefully. You never mentioned ITU standards like G.651 or 652. Again possibly due to time. It's actually a hodgepodge of network cable out there all working differently at different lengths of regeneration points. The advances in Switches and Routers has allowed for full use of these hodgepodge networks. By the way I have been a loyal fan for years now, and this subject should not be a tech quickie but I will say this was an admirable go at it, and a very good explanation. I know veterans in the field that could not explain it to a customer as simple and as graceful as you did. As I recently became a TH-cam creater I know how hard this is. Props to you and your staff Linus!
The channel is called Techquickie for a reason.
@@sliwka621 I am sure Linus would appreciate you trying to help him. Unfortunately, the differences between single-mode and multimode are so simple they can be summarised in a single sentence or a few sentences if you want more context, is that not quick enough?
@@edtheoldtechguy That's true but I got the feeling that he was talking more about long distance transmissions and for that we only use SM. There are some not so smart clients who want MM lines kilometers long but they are very few in between.
@@sliwka621 Linus began the discussion with what fiber was. A sentence or 2 differentiating MM and SM and how they both conquer long distances, would have been stellar. Then adding the limitation of LED-based light vs Laser and why SM is used for greater distances would have clinched it for me. By the way, multimode is used in metro areas to tie buildings together so while it makes no sense as a interstate communications medium, it is used many times in dark fiber loops that connect buildings like hospitals together. Not my suggested way but it is the cheapest. MM does achieve great distances when compared to copper. So by skipping it I think the tech quickie lacked. Linus is not a network WAN engineer yet I complimented him on his effort and even told him that many veterans could not done as well.
"Look at light at molecular level". Oh no!
what
as a wave or particle then ?
that doesn't make sense
@@nobitanobi3475 hmmm, I wonder
So, do you need light to see light on a moleclar level?
I had a endoscope and a colonoscopy and i was afraid they would meet in the middle
where is the middle
somewhere between the intestines and stomach
I always wondered why the other one wasn't called an endoscopy
I always assumed the endoscope was the scope the doc shoved up your Endo.
Endoscopy is a general term for an examination where an endoscope is used. It can be esophagogastroduodenoscopy for the upper digestive tract, colonoscopy for the lower intestines, cystoscopy for the bladder, laryngoscopy for larynx, rhinoscopy for nose, bronchoscopy for the airways and some other endoscopies for other organs.
Job Recruiter: what are your qualifications?
me: i watch Techquickie
Job Recruiter: you're hired!
No joke, this basically happened to me. I watched a lot of Linus Tech Tips videos and then ended up getting a job at a PC shop based on my knowledge gained through these videos
Linus media group: "great news, guys! We are hiring again"
@@jerrystuarts9917
Linus HQ : " so...tell me how do yo know about technology?"
that guy: "uhh,by watching your videos?"
Linus HQ: " welcome to Linus group!. here's your papers and we expect you to came tomorrow. speaking of going to work,we recommend you using uber. with 20% off by using code hiredatlinus"
Redstone repeater: hold my beer
When he said treehouse and transmitting messages, I thought he was going to go the cups on a string route, not morse code..
Same
Ahh this took me back to when I was a telecommunications technician. I genuinely enjoyed learning about how the internet was created. I do miss it alot.
Now I know what inspired redstone in Minecraft. :D
I think it's just a coincidence, Notch pulled in Minecraft a lot of irrealistic stuff, like azure diamonds to say one.
Azarilh you think it’s a coincidence? It was intentional, redstone is just Minecraft equivalent of electricity.
@@xehP "Equivalent" I studied this stuff at school, it's not "equivalent" at all, it's just similiar.
Redstone is more like gunpowder and when its used, it carries a charge. It also sounds more like electrical engineering than fiber optics. What it makes it sound like redstone is because Linus just mentioned repeaters.
Azarilh wow you have education? Damn, I’m really jealous... it’s the equivalent. You sure you studied electrical engineering? Assuming that’s what you’re referring too.
Thanks for shedding some light on this technology.😄
Linus's annual physical is not the image I wanted in my head this morning
0:42 I expected a jumpscare there *sigh*
I was so ready to ALT+F4 at that time....
@@albert328 haha
@@albert328 that is creepy as fuck
It's amazing how accurately you've portrayed this information in such a short and simple manner
The simplest, mos informative explanation I've heard so far. Thanks.
Over long enough distances the signal weakens?
Is that because fiber optic cables are always eating light? That must be why they're so thin.
new diet!
The phenomenon is called TOTAL internal reflection but in actuality it's ALMOST TOTAL internal reflection. Some portion just passes through the glass. That's why the fiber cable itself appears to glow throughout it's length, if there was TIR, light would only appear at the end.
15 blocks then you need to place a repeater
HA! 😊
@@Stalka42 amplifier
0:44 “too dim to *MaKe OuT*”
Pfft like that stops anyone
actually a great question, i have wonderd this a lot of times. Thanks for awnsering this question for me
2:58 thats exactly redstone logic lol
THAT was a good segway at the end. Good job Linus!
If you rename the video to how a Minecraft repeater works you'll probably get more views
Comparator *
*Apple* we are very excited to show you our new iPhones
*Linus* but how fiber works
*Me* hmm let's watch linus
Apple: We're very excited to show you a new way to waste your money!
@@triparadox.c Yep
Also good to note about how light entering at different angles which limits the bandwidth possible as pulses have to be timed so no signal that is meant to arrive later instead arrives too soon
Dude this was a super informative video! Keep up the good work!
Feels I’m 16 and back in my a levels physics lesson
i am 14 and currently watching this instead of my as level physics
I didn't know about the differences in the glass layers. I knew there were many layers of glass. Thank you Linus.
Another LTT video used for my GCSE Physics lesson, cheers guys!
This is a great basic explanation. There are a few inaccuracies, however that could be corrected without making this explanation longer or more complex.
Modern optical fibre does not make use of total internal reflection - we could never really go much further than a couple of kilometres if that was still the case. It actually uses a refractive index gradient (as opposed to a hard boundary) to guide the light back into the fiber. Check out the difference between step index fibre and graded index fiber.
Repeaters vs amplifiers. Hmmm…to be honest these two terms are interchangeable, but they both just mean “amplifiers”, and more specifically “optical amplifiers” (like EDFAs, SOAs or Raman amps). You may have meant to compare amplifiers to regenerators - which digitally recreate the signal, as opposed to an analogue amplifier. Regenerating signals is expensive compared to just amplifying them, so the goal in modern long distance communication is to send the signal at the highest possible data rate as far as you can before you have to resort to regeneration. But you may still amplify that signal about every 50-80 km.
Just to note that optical fiber was used in endoscopy way before it was used in communications, at least in terms of commercial products. Endoscopy dates back to the mid 1800s using hollow tubes, but fiber endoscopy was invented in 1957. The use of fiber for communications was triggered in 1970 when two technologies reached a sufficient state of usefulness that commercial products could be created. These two technologies were low loss optical fibre and semiconductor lasers.
always wanted to see Nottingham
I know you've done tons of terrible segway before
But this one tops it
Just saw it, and now I need a doctor.
Not to take away how bad it was, but that is an equally awful way of spelling that word.
Segue*
Segway is a mode of transportation for lazy people. It is not the same as a the French transition "segue." Please learn the difference.
*but can it fix my broken heart Stacy?!*
F
Gamers rise up 😤
Thanks for the revision Linus, my gces are coming up!
0:23 Linus hologram shaking.
Can we all just take a moment to reflect on the fact that we all live in a time where humans control light to transfer data?
And we use it to transfer porn.
Learned more about fiber optics in 5 min than 1 year of IT Course.
This is a great video for introducing the concept. Thank you
Just a little correction, the total internal reflection is a geometric property of light.
Scattering on the other hand is actually physical property.
LTT 2039: We just bought and overclocked a colonoscope! Time for Linus' annual checkup!
Good way to plug his underwear.
Let's watercool it
I did not know I needed to know this but it was actually really interesting
I’ve been installing fibre for around 2 years now. it can be very challenging at times but I love it
Multiple light waves can be sent through one fiber and at amplification points the light gets separated into the individual waves amplified beyond the necessary strength then subsequently reduced in strength to a more precise signal strength at which point the individual waves are then re combined or multiplexed and sent back through the fiber on the other side.... some of these systems are fully reversible others are directional depending on its function.... this gives us the capability of pushing over 400gb/s over a single fiber run
This is true but not the full story about fiber optic networks, nowadays to use every space there is inside the fiber, multiple carrier frequencies are used (different colors). This is then multiplexed together and demultiplex at the end which is often done with a simple n-th order filter, giving the individual 1's and 0's back for each wavelength.
Very good vid. I work in low voltage/data/security and some splicing from time to time.
Such a smooth segue. Best one yet.
I hate when somebody throws a wrench into my pudding!
first time that video notification popup within 1min of upload , usually it pop after 10min 😂😂
@@Drdrew1234 I understand n can read english, just not to fluent in speaking, like 2-3 word per year except for brand names 😂😂
Why is this funny?
Thank you so much for explaining this! Very helpful!!
Nice that finally shed some light on the subject
3:00 he is speaking the minecraft redstone languange
Edit:thanks for the 11 likes:)
I tip my hat to you,one legend to another
@@gigibecali699 ohhh shittt
lol
Let me watch the Apple event first. Liking this video as of now btw
And who are you?
scat you verified normie!
Thanks again Techquickie for your explanation again, like to hear more, kind regards
Love it.. good work linus with information.. you should participate in some historical episode explaining computers and electronic engineering 😉
I remember when I was a kid in early 80s, I shined a flashlight through a metal tubing. I've noticed the light would seem to bounce off the reflective walls in the tube making the light shine bright to the other side. I was thinking maybe I could use this to connect between two places with long piping and use it for instant Morse code without using radio. I was a smart kid back in the day. I don't know what happened lol
Very well explained! Thank you.
Having studied communications & signal processing at the undergraduate & postgraduate level, I'm happy that this topic is gaining public exposure. I have to point out that wireless signals (4g, 5g, wifi, bluetooth) also use light to carry data, these use the microwave, while fibre optics use infrared. Both are invisible, so I don't know why you just explained fibre optics alone
@Techquickie
Very interesting, thanks.
A question: Considering how fast signals through fiber optic cables can be, why did video and audio systems prefer HDMI and/or DisplayPort instead of fiber optic cables?
I think that setting up the equipments to produce and read the light signals would be expensive for average consumers. And also idk if you remember it but in one of his videos last year or 2 years back, he used a thunderbolt/hdmi cable using fiber optic technology since his PC and his monitor is very far apart and there are no regular hdmi/thunderbolt cables that can transmit signals over that long distance
Fiber advantage is distance of transmission, not latency. Latency only becomes a problem when repeaters get involved and this is required when signal level degrades, which is faster in copper. For short distances, this isn't a problem. Also, HDMI has more on it than just digital signals. It also has auxillary power which cannot be transmitted over fiber.
Audio systems use electrical signals that are amplified by speaker amplifiers. Before the amplifier, optical cables are possible but don't provide any benefit. After the amplifier, optical cables are not possible because they would lose all of the wattage needed to power the speakers.
Please explain why Spectrum (the ISP) has such bad upload speed but okay download speed. Pretty sure TCP works the same way both ways.
Because they throttle the speed on their end when they receive it and send it out to you.
th-cam.com/video/RLooclrz7wA/w-d-xo.html
I forgot if he covers DSL vs ADSL in this one.
Every ISP does that, it has to do with symmetrical and asymmetrical connections. Just to make it simple, asymmetrical = cheaper, symmetrical = expensive
iukeay I have them and I haven’t had that issue at all, my issue with them is the random outages and it going off during the middle of the night when I’m gaming.
It's because there's way more people who watch TH-cam videos than there are people who upload them. The ISPs allocate bandwidth accordingly. Linus Media Group has a symmetrical 10Gig connection to the Internet.
Thanks a lot for explaining it so well my concepts are cleared now thAnks once again.
Just what I needed. Thanks!
3:13 exactly like minecraft
Im fiber optic technician
So i know :)
You know the one rather major flaw in the explination?
Please make a video on how Water could be used to store data. There is enormous research going into this.
His guy is a legend! His energy and simple beginning is top tire ❤❤
Great, now can you explain why I've been waiting for 5 months to have my fiber installed to my house?
It's so obvious that everyone is watching the apple event right now lol
xD
Apple Event gets even more cringing this year.
@@allansh828 Ikr! The amount of times they say "We're so excited for" or "I'm so excited for" is absolutely stupid!
Just scheduled a colonoscopy yesterday. Thanks for lightening the mood/slash making me think about it again, Linus.
Setting up fiber optic networks is by far the best job I've ever had!
Why is no one watching apple live stream?
Because
"Insert segue to our sponsor"
Because most of us are peasants.
@@mizunochie I tuned in for 1 minute, the energy is sooo low ROFL, and somehow 1.8m people are still watching
@@Mr.Meeseeks024 yeah shits a joke lol
And that evet was bad. Nothing new really
@@pekkapeltola2642 it was terrible, at least the 60 seconds I saw.
It's like RGB lighting, but really, really fast.
I worked in this field with EDFAs before the telecom bust. Each fiber in a 40km link could handle 80Gb/s through muxing different wavelengths of light onto the single fiber. We developed 32 ch systems that had EDFAs(erbium doped fiber amplifier) which used a 970nm laser pump to amplify the optical data stream, in phase, by 16dB. The technology was pretty amazing even for an EE like me.
Did I miss the source for the map @ 3:45? I hope for more educational videos to include citations in the description!
When you are early but the video is loaded
Yeah this is big brain time
Wat
I want riley, Alex, and James tech tips
I want money.
Interesting choice of having a photo of a SonoScape endoscope. I was really wondering how well it performs in Canada because I used to sell them in my country and nobody heard of them. I also assume it was just a random photo of images search.
This definitely helped me on my Networking report for college
...And important data...
Me: MEMES
I thought you will say, "I know where the doctor got his degree,..... 'BRILLIANT.ORG'"
You could also have mentioned what type of light and which wavelengths get pushed through the optical fiber. And that there can be an issue with light representing a single bit bouncing around in different angles resulting in blurry bits instead of hard on/off edges.
Remember this is Techquickie; most of the target audience wouldn't have that level of understanding
The transition to the sponsored message was smooth AF.
They made repeaters from Minecraft a real thing. Smh
In future I believe UV-Ray and X-rays could also carry data
UV probably but Xrays can't currently be sent through fibers like visible light can. Although, yes, they could transmit far more data than visible or IR (which is more common right now)
UV scatters alot so it's impractical ..and x-ray..nope! Unless you want cancer
.
.
.
Although UV also causes cancer
@@Kiba114 I disagree - it's a legitimate question, because x-rays can transmit far more data than IR. I hope you're not a rtfm person....
@@Kiba114 I'm not saying it will happen or should happen or anything I'm just saying that it's a legitimate question to ask why it hasn't/will not happen.
@@Kiba114 I'm just trying to defend the original commenter, and I know that it's just one Google away but I'm kinda running out of patience so I'm going to end the argument here.
i always like linus's vids for his Ad transition
Good to see linus talking about physics!
God said, let there be light
Then there was light and all was well with the gamers
with no lag. amén
Okay!
But How Does LIGHT Carry Data?
Ma man's gonna teach me this for my exams!! HELL YA!
LTT - science , news and tests.
Techquickie - Things you probably didn't know.
You should rename the video. This is more along the lines of "How does fiber optics carry light"
Linus Minecraft playthrough when?
Watch out mumbojumbo, here comes another professional
bro linus vs mumbojumbo redstone would be the most lit thing ever.
Always wanted to know this !
Thank you Linus, very cool!
2:54 "minecraft players have entered the chat"