Please support us and make our efforts sustainable - www.patreon.com/Lesics

@Tecworkshop

5 жыл бұрын

There is a Hindi language channel, which does not have Bangla language in English language channel

@manujgupta

5 жыл бұрын

Sir how you edit videos please tell us

@Tecworkshop

5 жыл бұрын

We want a video in Bengali

@Tecworkshop

5 жыл бұрын

Sir, you are a great Engineer, # I respect you ♥💛💋

@Steamrick

5 жыл бұрын

Mistake at 6:25 - electrical signals are transmitted through copper at ~2/3rd the speed of light, almost the same as what fiber achieves. (Actually copper is slightly faster according to most sources since the light bouncing back and forth between walls will increase effective travel length further.) Electrons flow *much* slower, but that's not actually needed for a signal to pass.

The people who invented all of these are the true geniuses.

@riseabovehate9476

4 жыл бұрын

Yes they are the nerds who got bullied in schools , they are the unsung heroes of human civilization

@rajeevkumarrajan4059

4 жыл бұрын

Narinder Singh Kapany an Indian American engineer

@hashimal3bdali867

4 жыл бұрын

It just came step by step nothing samrt at all

@mareomanojdominic1498

4 жыл бұрын

@@hashimal3bdali867 says the guy who cant spell "SMART"

@anamikakashyap2707

4 жыл бұрын

Narinder Singh Kapany invented Optical fibre, the unsung hero.

What I learned from this video.. Optical fibers 1. thickness comparable to that of a human hair. 2. transfers data at a very high speed because of the use of the light as the carrier.(or we can say that they carry information in form of light),(due to this we are able to do this exchange of information in an only blink of an eye.) Principle : It is based on the principle of Total Internal Reflection of light TIR: a) when light travels from denser to rarer medium it bends away from the normal. b.) angle of incidence should be larger than the critical angle. Critical angle: angle at which the refractive angle becomes 90 degrees. structure of the optical fiber: core: innermost part of the optical fiber. and light travels through this part of the fiber. cladding : middle part of the fiber having refractive index less than the core in order for the total internal reflection to happen sheath: the outside protective layer of the fiber. material used: mostly these optical fibers are made of glass(silica) or plastic. In case of using glass as the material, both the core and the cladding are made of the glass and some dopants are added in order to make cladding of lower refractive index. attenuation: this is the loss of the power of signal. Could include various causes like scattering, absorption etc. So there are amplifiers installed at certain distances to again power up the signal and cover up for the losses. Now whenever you send some information through your phone, your information is converted into a code of 0's and 1's, based on already set parameters. This converted signal is send to the tower in form of a wave, where 1 is send a high frequency while the 0 is as a low frequency. now at the tower if the electromagnetic wave is of high frequency then a light impulse is generated, otherwise for a lower frequency no impulse is generated. As we also know that amplifiers are installed at certain distances to cover for the losses during the transmission (this loss we termed as attenuation), now the question arises how we will be covering up for this loss when these optical fibers are laid down under the sea and oceans . Here the cable is much larger in diameter and only very small part of it is actual optical fiber that is carrying the signal. The outer part is the protective coverings. so here a copper shell runs in the cable itself to supply power to the amplifiers. optical fiber vs copper cables 1. as the speed of light is always more than the speed of electrons, the optical fiber cables transfer the information at much higher speed. 2. also the flow of electrons inside the copper wire produces a magnetic field and thus is at the risk of magnetic interference due to some outer field. first the optical fiber were used in endoscopy, here the doctors can see what is happening inside the body of the patients. (the reason to do this is to not just become a consumer of content, but to actually understand and write it in your own words so as to activate neural pathways in the brain).

@scundoorsup5342

2 жыл бұрын

You might as well also learn the true origin of this photonic marvel. We acquired it not invented it. Big difference. Remember this fact . We are only 1% genetically different than Chimpanzees . If you think a little harder , you will be free of govt/ military propaganda . Time to teach the children well.

@dondominic7404

2 жыл бұрын

You should make a good teacher

@priyankajamdade5359

Жыл бұрын

Supeb

@aerodynamico6427

Жыл бұрын

What you did NOT learn: Narinder Singh Kapany (31 October 1926 - 4 December 2020) was an Indian-American physicist best known for his work on fiber optics He is credited with inventing fiber optics, and is considered the 'Father of Fiber Optics'. Fortune named him one of seven 'Unsung Heroes of the 20th century' for his Nobel Prize-deserving invention. Dr. Kapany was also on Time Magazine's list of top ten scientists of the 20th century in Time's last issue of 1999.

@keshavarora6814

Жыл бұрын

@@aerodynamico6427 thanku buddy 🤟🤟

Really great information. Optical fibers really are quite fascinating! Another really cool thing is that you can use up to 80 or so different colors of light (or wavelengths of light) in a single fiber, it's called wavelength-division multiplexing and it increases the bandwidth by 80x!

@Kabodanki

5 жыл бұрын

Limit of fiber optic is not the fiber optic itself but rather everything on each end

@harshsinghal4342

5 жыл бұрын

You should also make a video on it.🙂

@JimGriffOne

5 жыл бұрын

Same as using different radio frequencies. In fact, if we could make lasers that produce frequencies of our choice, we would be able to do much more than just TDM/FDM/WDM. The theoretical bandwidth of optical fibres is so high we haven't even begun to exploit it as a data transfer medium. Rather than using pulses of light, we could use other modulation methods like ASK, FSK, PSK, etc. The physics technology isn't there yet, and computers wouldn't be able to handle the throughput, but it's amazing to imagine the possibilities!

@Blox117

5 жыл бұрын

i like staring at lasers

@Lesics

5 жыл бұрын

Thank you for the valuable information.

My biggest question about fibre optic cables had always been "How does the information travel through the fibres?" Now I understand...when your device sends out your message (eg test message), nearby transmission towers convert it into binary numbers (1s and 0s), then every 1 travels as a light pulse and every 0 travels as the opposite of a light pulse (i.e no light pulse) through the fibres. On the other end, the receiver converts all light pulses into 1s and all no light pulses into 0s, then the ones and zeros are converted into machine code, which is then converted into human language that you can read. Amazing to learn this today.

@MrKevin-wu8re

Жыл бұрын

Then stuff starts to get complicated once you get to compilers, software, web apps, streaming, and so on lol

Two minutes and fifty-seven seconds in, and I was blown away. I've heard that engineers tend to think man can do anything, and no wonder! Look at what we do now!

@tayvioncole8731

3 жыл бұрын

Can we fly

@klipk7296

3 жыл бұрын

@@tayvioncole8731 Yes

@Djentstructer

3 жыл бұрын

@@tayvioncole8731 In a plane, yes.

@drewpeacock3678

3 жыл бұрын

12 seconds in I had no clue that fibre optic cables stretched the ocean floor that am impressive concept

@Cynane27

2 жыл бұрын

​@@tayvioncole8731 There's a video of a guy paragliding on a sofa couch. Think that's close enough

When the instructor said the light can only be sent 100km before needing to be re-amplified. I was wondering how do they get it across a whole ocean? Man i was on the edge my seat till i got the answer. What great illustration of how this works. Thank you!!!!!😃😃😃😃🤪🤪

@mangning1107

4 жыл бұрын

amplifiers are also put below the ocean

I used to be a fibre splicer and it takes a lot of practice and patience to strip a piece of glass thinner than human hair. It’s fascinating to watch them join when the arc is fired by the machine. It’s just amazing.

@manleynet

3 жыл бұрын

Splicing now is really easy, just strip the outer layer clean it lay the fibres in the machine and shut the lid thats it the machine does the rest.

@djordjeblaga7815

3 жыл бұрын

@@manleynet Its easy for us because we are used to it. Hand a beginner a fiber and a stripper and they will absolutely break it. It takes a few hundred splices to be comfortable with optic fibers.

@scundoorsup5342

2 жыл бұрын

Then you surely must question the fact that we could not have invented this technology, alone . Think deeper, think harder .

Every single time I hear some kid on the internet say: "KZread is garbage, it's nothing but stupid trash meme videos and kiddy nonsense. You can't learn anything useful from KZread." ...I send them to this channel.

Thank you for the video. I am actually a medical doctor but really enjoy learning more about engineering! All the best!

I'm studying software Engineering in Zimbabwe with a local Varsity. I have a course on networking and um a week away from exams and this video just saved me. Good informative video. It answered a lot of my questions

@EternalNico1

3 жыл бұрын

good luck from america! hope you pass

@eugen1721

Жыл бұрын

It's great to hear that you're also learning about the hardware and conections that pass the information, and not just about things related to the software.

This was actually such a great video for people with no background in physics like me. Thank you!

Amazing concept behind Optical fiber cables! Light, signal, Refraction, TIR, Modulation, bits, EMW are the core elements in OFC. Thanks for the wonderful explanation!

Great video! There are some heavy inaccuracies though. The two big ones are: -The speed at which information travels in the copper cable is not necessarily less than an optical fiber!!! Its speed is given by c/n, where n is the root of relative permittivity of the material, it has nothing to do with electrons!! The reason why optical fibers transmit more information is due to the fact that they have a much greater bandwidth. -Copper cables are usually coated and do not leak EM fields, especially at higher frequencies.

@idlehour

2 жыл бұрын

But the rate of speed isn't equal to the speed a tiger can run. Even not the even level. The truth is rain because i had a dream last Night after taking medicine for a tumor in my GI tract. The negative reaction is on the negative side cause thinking is like playing Farmville. That is to say its confusing and i have a feeling even though they said they kept the tiger alive after he ran the cable to cabin to cabin, home to house, farm to ville. I think they put him down after because I do not hear about/from him anymore. Or maybe i just broke a arm again and forgot for a week

@Fedelisk480

2 жыл бұрын

@@idlehour Your Point? Also, English please.

@idlehour

2 жыл бұрын

@@Fedelisk480 This was typed in English. But because you are confused. And felt the need to question. It is. . . . Убийство во имя

@payindah4414

2 жыл бұрын

Tysm, confusion get cleared

@Fedelisk480

2 жыл бұрын

@@payindah4414 no problem, glad to be of help.

1:49, just casually injecting some glass with dope

@anishshinde1184

3 жыл бұрын

Lol

I cleared my uncleared topic for many years from school age to graduation thank u so much.

fiber optic cable, high speed internet access

@MastiShorts9211

2 ай бұрын

Please help me, I am from India, I have created a new channel, I also make videos on optical fiber cable All Fiber Solution youtube.com/@FIBERSOLUTIONSPLICE13884?si=V0hLFw_O5nOVdhD1

Better than teaching in a classroom. Thanks for posting this knowleageable ideas.

Thank you for giving this wonderful concept

The best lecture on optical fiber ever seen🔥🔥

Great video so far. I really love that channel and your projects.

Very informative. I loved it and the power of simplicity.

All your data is just instructions which can be translated in a light turning on and off. It's just amazing.

Thank you. You clear all my quarries in single video.

Beautifully explained!!

It was first used to make decorative lighting inside the home. I’m old.

@70ixlr86

3 жыл бұрын

While i remember the decorations as well, one must realize, this is not that type of cable. At that time is was plastic, and while it did a very similar transmission task, it was not as thin or as dangerous as the inner core of our fibers used for transmission of data. The inner core of data fiber is to be treated as very dangerous needles. They are hard to find once in-bedded in skin. And are now a flexible glass.

@Gabriel_Moline

3 жыл бұрын

70ixlr8 Right on.

@tpeter5866

3 жыл бұрын

The decoration light is not optical fiber cable. That is made only for decoration. The one used in optical fiber is way too thin.

I should have come across your channel when i was much younger. Thanks for your efforts

I didn't major in engineering and don't know much about it. But I always have the curiosity. Thank you for this video!

@scundoorsup5342

2 жыл бұрын

All you have to know is that we did not invent this technology I know it’s hard for you to believe other than what our govts tell us , but think a little harder before you declare how fabulous slightly advanced chimpanzees we are .

@eren_yeager9927

6 ай бұрын

@@scundoorsup5342 We engineers really did invent pretty much the vast majority of technology we have today though, we are problem solvers and technological innovators, we are scientists but with practical and prospective concerns. Engineering is the profession why humanity is now a very technologically advanced specie and we take that for granted.

@scundoorsup5342

6 ай бұрын

@@eren_yeager9927 while you may have found out how the fundamentals of certain laws of physics behave , you can’t with a straight face lay claim that all this technological convenience is human engineered . You must know this .or maybe not. Research graphene, holograms, cloaking , laser and laser projection etc etc . It’s like a pharmaceutical company claiming they have found cures or more accurately bandaids and symptom treatment for all of man’s ills. How is that working work us ??$$ Engineers are funded . Funding flows when results are in favour of the funder . This is well known. Sadly . Do more critical thinking . Question outside your training parameters and for god sakes, believe in your instincts .

I was studying ray optics and this concept of Total internal reflection made me think of its application irl but i couldn't think of even one and when i searched it i found this and whoever invented Optical fibres is a Pure Genius.

yo dead ass great videos. i dont know how you guys do it but the way you explain it makes so much sense

Thanks for this video~ I have a report on FDDI 2 and didnt have much information gathered online so i turned on how fiber optics transmit different types of data. I'll present this video in class it's great!

Awesome video! This really helped me understand just how these cables work. The chapter from my fiber optic textbook failed miserably at it.

@noramo2899

3 жыл бұрын

good

Just a tiny note. The speed of electrons in copper cables is slow indeed, but it doesn't really matter for data transfer. What is important is the speed of electromagnetic pulse which is close to to the speed of light as in the case of optical cables. Still, optical cables are much more efficient than copper ones.

There can be no better explaination in this much limited time for this topic...very well explained...

THANKU SO MUCH...very simple way to understand

we had taught this when I was doing my engineering. but I understand whole concept now. great explanation

Mistake at 6:25 - electrical signals are transmitted through copper at ~2/3rd the speed of light, almost the same as what fiber achieves. (Actually copper is slightly faster according to most sources since the light bouncing back and forth between walls will increase effective travel length further.) Electrons flow much slower, but that's not actually needed for a signal to pass.

@NoorquackerInd

5 жыл бұрын

you're right, electrons move very slow, ElectroBOOM made a video about how it's coulomb stuff that can calculate the slow electron speed, but the main reason for fiber optic supremacy is its lack of interference and its fast rise/fall times compared to copper

@Blox117

5 жыл бұрын

electrons travel very fast, they're just shy when you look at them

@Steamrick

5 жыл бұрын

@Noorquacker exactly, it's the lack of interference that makes fiber optics so superior, but that's a different kettle of fish entirely to the speed that electrical signals travel at. Interference was actually mentioned in the video, so I'm satisfied enough on that point.

@DimitriPappas

5 жыл бұрын

Aren't photons and electrons basically equivalent? To differentiate their speed does seem like a fallacy - I noticed this too

@joshnel123

5 жыл бұрын

The increase in bandwidth also you can cram more pulses per second in a fibre cable without data corruption. They are working on fibres now which have a group velocity very close to the speed of light and a effective refractive index of less than one this would make fibre optics even faster. These fibres are called negative curvature fibres.

This channel has really great content.

Wow! How beautifully simplified.

I knew I was a 'A' student if only my physics teacher was this audible... Look at me now trying to relate my wasted life because of the grade I got all thanks to the teacher whom I can still not understand... Thank you for the massage it's really helpful

@humbleandsimple7903

3 жыл бұрын

Through your experience. Any advice? I am 16

@vickotin9317

3 жыл бұрын

Yeah...just be more ambitious with what you want to be...make it fun..work smart not hard...don't be be compromised by the negative energy👍👍👍

@randomspectator39

3 жыл бұрын

*"massage"*

@mrtom-a-hawk6732

3 жыл бұрын

@@humbleandsimple7903 Set a life goal, a mission of how you want improve the world, and focus on that, ignoring what anyone else has to say.

Having seen this video, I have learnt much about optical fiber. Thanks. I am from Pakistan

The information this channel gives us is well prepared and the animations are too good...

Wow! Love the visuals. I really wasn’t familiar with optic fibers, now I’m beginning to understand.

I have a "optical fiber" course this semester ! Your video helped me to get an idea about it thank you !

@riteshsharma9813

3 жыл бұрын

Yes

Thank you so much. I really appreciate your effort of creating tutorial videos like this to spread your wisdom to the world. Please make more videos about networking, it's really helping me a lot. God bless ❤❤❤

@MastiShorts9211

2 ай бұрын

Please help me, I am from India, I have created a new channel, I also make videos on optical fiber cable All Fiber Solution youtube.com/@FIBERSOLUTIONSPLICE13884?si=V0hLFw_O5nOVdhD1

Our IT teacher has tought us nothing, thanks to this I have some basic understanding.

Thank you for increasing my knowledge... Keep it up

Thank you so much for these videos! Love it! ❤️❤️❤️

@haitembujohannesmabizela2329

5 жыл бұрын

love your comment hey....

Just saw this in my physics textbook and it looked interesting so I thought I should look into it......i don't regret one bit.

Great video. Thanks! This helps me studying my exam.

I've never seen such a great way of explanation ...

I find hard to comprehend it's network and how on Earth any person think of inventing such thing... No words...

This video is a masterpiece 👌 It deserves millions views

Thank you for giving a really good animation video for better understanding of OFC.

Just amazing 😍After watching this video I got all answers of my questions which wondering in my mind

understanding complex subjects of physics is necessary and helpful !! Your videos are nicely clear and well explained!!your efforts in preparing your videos are very grateful. Thanks very much. I subscribe, like and share. Good lucks.

As a Fiber Engineer i approve this message!

@joancarlopimentel3263

3 жыл бұрын

And here I am with old dsl internet that’s wack

@bulanmarkramill.3278

3 жыл бұрын

Will it be okay if I ask some questions sir Alex? 😊

@MenacingPerson

3 жыл бұрын

@@joancarlopimentel3263 hahaha your DSL also uses fiber believe it or not

Thank you for this astonishing explanation.

Amazing technique..well explained 👍

Really nice information. Thank you so much for this video.... :) I always watch learn Engineering to improve my knowledge. Once again thank you so much for making these kind of videos learn engineering....

0:06 I thought he were going to say SQUARESPACE.!

@farel-168

3 жыл бұрын

lol

@farel-168

3 жыл бұрын

too much linus

@mmshasan

3 жыл бұрын

🤣🤣🤣

@abdillahihassandjilal8867

3 жыл бұрын

Yes

@supercoolmunkee

3 жыл бұрын

@@farel-168 Techically just about every KZreadr these days are getting sponsors from Squarespace and not just Linus. Other content creators are getting all sorts of sponsors to help promote their videos and their viewers.

Clear explanation. Thanks for the efforts

What an absolutely amazing video! Great job!

feeling naughty? go scuba diving and cut a fiber optic cable and take out a countrys wifi

I thought I knew all of this from networking class in school, turns out i didn't, thanks!

your video helps me studying ict. this video says interesting understanding about optical fiber and the unseen.indeed we normal people use internet every time but know less about the actual science and technology , Thanksgiving for your hard work

best video ever seen on youtube , thank you @Lesics

AMAZINGLY KNOWLEDGEABLE THANKS

Good information

Please continue with giving us such wonderful informations

Great information.Thank you Sir We need such discoveries 👍🏻👍🏻

I got optical fiber today and the speed is so good and stable

@eamonn1979porter

3 жыл бұрын

Must be nice ☹️

during refraction when light travels from rarer medium to denser medium it bends towards normal and when it travels from denser medium to rarer medium it bends away from normal.Right!!!

Really great information. And best graphics design

I still don't understand the internet. Like its literally just magic at this point

@imremolnar5585

2 жыл бұрын

Check Lecics's video, the title is "How does the INTERNET work"

@micspamgod2324

2 жыл бұрын

It’s complicated but not really. All the internet is, is a network of computers. You have to have server towers that have the data, that data is sent out to everywhere. The data is hosted wherever, think of Google. Everything with Google is stored at Google’s data center. When you look for something from Google you’re searching from their data and using the internet to receive the data(actively downloading as you’re searching different things.) I’m not expert but this is a basic sum up of how it works. It’s a network of computers, you search for things or do things that’s connected to them even if it’s super far away. :)

I don’t know why I clicked on this video but it was very interesting,

one of the best content creators ...tnx for the fabulous explanation hope to see more and more....

amazing..!! this project should be financially supported by education agencies around the world (y)

It is true that electrons move really slow in an electric circuit (something like 0,003m/s but it depends on some parameters) but the signal is transported with verry high speed because of the electrical field. The superiority of glass fibers is that, they don't have parasitic capacitence, inductence or resistence as metal wires do have

@cddum4992

2 жыл бұрын

I am not a hater. The video is great and i gave you a like. That was just a small mistake you did. Trust me, i am not a hater

@boggless2771

2 жыл бұрын

@@cddum4992 yeah good point. But do remember the electric field is slower than the speed of light (and hence the electric field) within the cable. But apparently it is still faster than fiber according to this guy: networkengineering.stackexchange.com/questions/16438/speed-of-light-in-copper-vs-fiber-why-is-fiber-better Really good read.

@cddum4992

2 жыл бұрын

@@boggless2771 this is exactly what i wanted to say, the magnetic field is slower, but i didn't find mey words to say it.

@Ignisan_66

2 жыл бұрын

@@boggless2771 Electric fields are not slower than light. They propagate at the speed of light because electric field and magnetic field are the things light is made of. Light is just electric and magnetic fields that propagate through space at c (speed of light).

Electrons flow really slowly. Like in the order of mm/h. It's the electromagnetic waves that propagate down the line at some quite high fraction of c.

@requen

5 жыл бұрын

But atleast you don't need a high flow for them to do work :)

@abhijeetgoldberg7605

5 жыл бұрын

Yeah! good question I also know that under normal household conditions Drift velocity of electron is in 10 to the power -4 meter per second

@LetsPlayTheMoment

5 жыл бұрын

I don‘t think, that‘s right. When there is an eletric potential (which is the case in our household electricity) electrons will move much faster.

@abhijeetgoldberg7605

5 жыл бұрын

LetsPlayTheMoment I am not taking about the velocity of Valence electron . But I am taking about drift velocity That means Velocity of Valence electron in the opposite direction of the electric field generated by applied potential difference

@ErikB605

5 жыл бұрын

@@LetsPlayTheMoment In household electricity electrons won't flow at all since the it's ac-current.

It's.. really contains amazing content... Thankyou for sharing such kind of content .❤️❤️

your videos are very useful for my education. thank you so much

Low ping is achieved. But best routing is also important.

That's interesting. So now question is how the light is converted into electrical signal whenever the light is reached at the destination? what is the mechanism used to convert that light into data (e.g. 101100). Can you please make more detail on that topic in another video or if there are already made video please share. Thanks for such exclusive interesting education.

@lachlan7181

2 жыл бұрын

A camera can take light ad use glass and mirrors to create a digital image. I don't know much about this stuff but i assume the same thing happens with the optical fiber, maybe it goes through mirrors and glass to be translated to digital

@scundoorsup5342

2 жыл бұрын

Does it not make you wonder that as we are only about 1% different, genetically than a chimpanzee and yet we have invented such a complex technology?? Think a little harder middle class robot

@aloneking9113

Жыл бұрын

these optical cable is connected with network towers which pass a specific energy in light to convert it into a signal

@godsonfialor5014

Жыл бұрын

In a simple way, I think the reciever at the destination end is designed with photodectectors and Electronic circuits that converts the optical signal to electrical signals

Very useful information every individual have to know,not as a subject but, as a knowledge

This is so great Thank you a lot

I learned all this in my final year semester..but now forgot most.

it's very helpful. but i wanna know how can these cables be placed under the deep seawater.

@westonwheeler2311

5 жыл бұрын

Water proof casing

@justquran4043

4 жыл бұрын

By ship optical fibers are placed under seas. I saw video about it

@crazysanta6641

2 жыл бұрын

ALENS

Thank you for the wonderful video. In 7.30 minute you have explained so nicely, one of the most important topic relevant in today's world. Dr. Amit Kumar Agarwal

The most easily understandable video ever thanks ☺️

Well illustrated :) In your comparison between fibre optics vs copper (speed of light VS speed of electrons), I think I get how the information gets transformed into electric signals, but how does the information get transformed into light?

@lachlan7181

2 жыл бұрын

Lasers i think

Is the optical fibre used in Fly by light system

Easy to understand by watching video rather than reading about optical fiber cables. Thanks.

Excellent explanation, I loved it😀👍

temperature effect on fiber?

@blackstar2008

5 жыл бұрын

None

@SuprakF1

5 жыл бұрын

It does.

@ramprasath4403

5 жыл бұрын

Not much... But maintenance cost., a lil bit of more care needed...

@MenacingPerson

3 жыл бұрын

If it goes over 750 centigrade then the fiber will melt

hello everyone my name is welcom

Thank you so much sir for your packaged information.

Typically Optical fibers are 125 microns in diameter. That is just the glass not the 900 Micron protective coating. Multimode and single-mode. Multimode is used for short-distance single mode is used for long-distance, multimode is an LED single mode uses a laser. Multimode glass is expensive to create do to layers to keep internal refraction at a constant single-mode cable is cheaper due to it having a single path. Multimode components are cheaper connectors and equipment. Single-mode is more expensive due to the higher tolerances required for a laser. Single-mode core has a diameter of roughly 8.5 microns, multimode has a inner diameter of 62.5 microns they both have the outer cladding to help keep internal refraction going. Good job at explaining fiber optics are so fascinating

Isn't critical angle=i for r=π/2 2:23 is that critical angle??

This channel is a gem 💎👍❤️