How a Laser Works
ฝัง
- เผยแพร่เมื่อ 4 มิ.ย. 2012
- Bill shows how the three key characteristics of laser light - single wavelength, narrow beam, and high intensity - are made. He explains the operation of a ruby laser - the first laser ever made - showing how electronic transitions create stimulated emission to give coherent light, and then how the ends of the ruby cavity create a narrow wavelength highly collimated beam. You can learn more about laser in the EngineerGuy team's new book Eight Amazing Engineering Stories www.engineerguy.com/elements
- วิทยาศาสตร์และเทคโนโลยี
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I love how mark hamil explains lasers
he should have shown us his lightsaber, I'd like to know how that works.
Samir Shrestha He's tired of Batman
Beam me up! Scotty!!!
Can mark hamil explain how does mark hamil explains light ?
This is Clark Hamil, his lesser known but much smarter older brother
And now we use them to fuck with cats.
We use them for almost everything.
+Cortster I use mine to point out stars
i use them for blinding cats
Holy Crusader your cruel
*you're
I know the words, but I don't understand them in that combination.
I understand some of this. Hugh school chemistry will teach you some of this stuff.
John Stuart Hugh School? Hugh Mungus has a school?
Jay Kay lol. Yes, I have the winning lottery numbers. Just have to get the right order.
Jay Kay, those were my thoughts exactly.
Thankfully you're not alone.
In the early 60s, somebody wrote 'The laser is a solution looking for a problem'.
sounds like hysteria to me
+myearshurt Noone it's based on an old saying "hammer looking for a nail". imagine your local overzealous neighborhood watch desperate to feel useful and trying to solve problems that are not actually problems.
basically back in the day nobody thought there was a use for lasers and laser advocates where just running around with hammers smacking at everyone's inventions.
spoonikle You clarified that wonderfully. Thank you.
"Laser inventor DESTROYS critics in this EPIC video"
Hapens quite often in the engineering world. I bet the people behind the creation of the LASER itself didn't expect much off it. Maybe just the Rangefinding aplication.
Hero of Alexandria didn't expect the Aeolipile to be more than a mere curiosity. It took 1700 years for someone to figure out the principles behind the device's inner workings and do something with it, and when it happened, it changed the world forever.
I have always taken time to explain how things actually work to my kids when they ask and having discovered your video's I am proud to say they were absolutely glued to the screen. TH-cam should have more educational material like this.
To bill directly you sir make the learning fun your selection of props examples and references are excellent. You have taken some very complex subjects and made them interesting and fairly easy to follow Thank you.
This guy looks 16 and 61 at the same time. (Loved the video.)
Wow hello there
Last place Id expect to see him
@@silkwurms same
It's the haircut.
why is this true
I'm not familiar with your career Sir, but if you don't do voice over and narration work then the world is missing out.
DPS he should definitely do a narration of that book he promotes at the end of every video. I would buy it
DPS check out his audio books
Not sure what it is, but something tells me he must be doing some tech stuff. Maybe even engineering..
Reminds me of bill curtis a little bit
This video is professional as fuck!
Totally reminds me of FilmmakerIQ
Could you please give me a definition of a professional fuck?
Prostitution?
A. Goraya lol
Unlike you
You should get paid by governments for making these high quality and very clear videos.
Anything the government does, it fucks up, or is vastly inferior to the private sector.
ZootMiBalot why not?
ZootMiBalot why?
Why not?
Lol everyone roasted you, but he is a University of Illinois professor, and is therefore paid by the State of Illinois in part to make these videos, as well as teach a class at the school introducing engineering to freshman and sophomores.
Dear Bill, thank you so much for so succinctly explaining how a laser works. I sort of had a general idea, but your video is so comprehensive and easy to understand. Science has always been my favorite subject, and being that I am writing one of my books on focusing, I decided to use the laser as an example of how light is focused, and your video was a God send in my understanding it. It gave me the tools that my tired mind from writing for the last fourteen hours needed to complete the chapter that my deadline requires.
Bless your heart,
and thank you very much once again,
Fredrick Fowler
Its been Seven years, How's Your book coming?
At the publisher now!
@@engineerguyvideo bill please make more videos
Excellent description of how a ruby rod laser works. Seen it in many diagrams over the years - but this explanation brought it all home for me. Well done!
Nice voice....good presentations...
but still didnt understand.
To understand how lasers work, first you have to already know how lasers work...
Maybe it's a teaser for a book.
@@ChesterChi3 what is this, recursion?
He uses too much jargon while making few attempts to define anything. His visuals are simple, which is good, but they attempt to cover too many concepts, which is bad. His sequencing is too rushed and lacking in transitional cues; he jumps from one feature to another without clearly concluding the previous feature or introducing the new feature, so part of your confusion is that you're trying to figure out how new information relates to the last when it likely doesn't; they simply share a theme of "lasers".
Basically, this guy is a prime example of why companies pay technical writers to explain engineers' products for them.
You need to know some at least beginner atom physics
I watched so many videos but that is the video which deeply clarified the working and the cause of Laser beam.
And this is why Cyclops's visor is made of ruby.
Ruby quartz.
They're not the same.
@@jonathanw1019 three year old comment....
Josefish that’s fine. 3 years, 90 likes and not a single person corrected them.
Somebody had to do it eventually.
@@josefish5193 The wonder of the internet is that it's not like you're speaking to an empty house, the message will still be there when the occupant returns. You can say something at any time and eventually someone will see it.
@@wsketchy Kinda creepy though, isn't it? We're constantly looking at the past as if it were present. Our future is becoming history within this space outside of time.
Thanks Engineer Guy! My students will love this as much as/more than I did!!! We're studying atomic structure.
engineer gaming
@@ft_lesserchungus1192 engineer gaming
I just realized he teaches at the college in my town. So cool!
what place, which college?
What does he teach?
@@worshipwithjonathan UIUC I assume, given what the caption shows at the beginning of the video when introducing him
You must visit
Im in germany, half way around the world haha
Love these videos! Your channel is often the first place I hear in depth about these remarkable feats of engineering. You're doing great work for laymen such as myself :D!
I love these videos because learning is fun, thanks for making some of the best videos on TH-cam.
Had to watch that twice, but I think I understand :D
I really love this channel .
You go precisely into the right depth needed to explain the most important functions.
There aren't many groups that will take the time y'all have.
I'd compare you to, mr wizard if I could. Maybe even better
+rocklobster1976 In my opinion, Don Herbert is the gold standard... (except for the two things I am aware of that Don (at least his researcher) got wrong).
--
Cheers
yeah
Wait what?
I liked it, it was very well explained, although I was hoping to find a little bit more information about the behaviour of the electrons and the different types of emission and absortion of light.
Very well explained. I knew about the ruby laser but I didn't know its operation. Great to have shown the ruby ball glowing when illuminated with blue light. Thank you!
These videos are fantastic, extremely well explained, and well thought out. Thank you @engineerguy
Made perfect sense thx!! Imma build one now
2:35 - 3:34
so, basically magic.
Jesus did it.
Lasers of Jesus would be an awesome band name.
I believe you're onto something my friend.
Alex Myers damkig
fotoelectric effect :)
You explain things so wonderfully and you respond to fan comments promptly. I am so damn subscribed. Keep'em coming!
Thank you, engineerguyvideo; I love your treatment of the subject matter -- it maintains comfortable rate of change in perspective that ensure the information sustains the interest of the viewer while staying close enough to remain an easy to relate whole. I'm glad I've subscribed.
Hey look, it's Mark Hamill!
i like his voice and what a great clip!
I have to say I read the comments before watching the video and I wasn't expecting to understand it because most of the comments say how complicated it is. Yet to my surprise I understood it and I really enjoyed it, looking forward to more of your videos!!
The most concise yet coherent explanation of LASER I have ever come across.
I still didn't understood completely.
It was interesting anyway.
If you had never learn physics before it maybe will be hard to understand, but if you will be able to understand the basic of it (Bohr Model) I think it will be clear - en.wikipedia.org/wiki/Bohr_model .
are you alive?
Me or the commenters above?
@@engineerguyvideo the commenters. Also how did you reply so fast?
I typed
When he said "ruby rod," who else besides me flashed to The Fifth Element?
you beat me to it, by a year no less. UNBELIEVABLE!
i already wrote this exact same thing.. you beat me to it by 3 months and dan beat me to it by a year haha
Dan sweetheart, what was that? ...It was BAD! It had no fire, no energy, no nothing!
Ya' know I got a show to run here, and it must pop POP POP!!!
So tomorrow from 5 to 7 will you please act like you have more than a two word vocabulary.
It must be green, okay?
I have the fifth element on a dvd
Nobody
this is the first time I saw an Arabic translation on youtube made by a non Arab great work thank you for your effort and to make your knowledge accessible almost to all human kind
your ability to keep things interesting never ceases to amaze me!
If they ever made Jurassic Park real, I’d like you to be the new Mr. DNA
lmao! dude, you nailed it!
Was lost by 2:30
If you had never learn physics before it maybe will be hard to understand, but if you will be able to understand the basic of it (Bohr Model) I think it will be clear - en.wikipedia.org/wiki/Bohr_model .
Very well done, my friend. Thank you.
sincere thanks for making this video
Where did you get the ruby from I want some
I understood up until 2:19 then I thought.......... ???? So basically I learnt they have rubies in them with some glass beads...... OFF TO THE NEXT SCIENCE VIDEO TO HALF LEARN SOMETHING!
+ReaLzEdits no glass beads. he was just using them as an example of a material that doesn't give off light and comparing them to the ruby that does.
***** See I'm fucked xD
ReaLzEdits ok you want a simpler explanation? see how the ruby shines when he turns the flashlight on it? make the ruby a tube, make the flashlight like a million times stronger, poke a hole in one end of the ruby, BAM, laser.
+ReaLzEdits the video do not explain "stimulated emission". and the picture is not correctly explain the population inversion. in stimulated emission, when light hit the electron to excited state, it will double the income light. Two "mirror" will reflect the light backward and this process repeat many time until "light" are very very strong to exit through the mirror. It is still over simplified but still better then not explain.
+ReaLzEdits "ruby shines in flashlight" is fluorescence not laser....
I remember reading about this in the book, "Lasers and Masers". Very nicely demonstrated. Thanks for sharing this.
Bill, we are very big fans of yours and must tell you that you present this video as if you are running late and have to catch a bus! This one appears rather below the "bar" you typically have for yourself. Thanks for the effort but you just might ponder this format! Best of luck!
Can you do one on green lasers? Their mechanism is different, and I would love to hear you explain it!
The principle is the same which you are still exciting electrons into a higher energy state and allowing the electrons to relax back to its ground state. But the material is different. The wavelength (color) depends on the energy difference of the excited state and the ground state for that is the energy the electron gives off when it relaxes. This would require different materials, many green lasers today are uses semiconductors as the lasing medium.
Not really, most Green Lasers are using an Infrared laser passed through a small doped crystal that changes the wavelength to green.
I believe this is what he is referring to.
MrMattsung Look up frequency doubling. Or second harmonic generation. Focused light passes through a non linear crystal where SHG effect produces wavelengths of half of the original.
Great video but the animation regarding the treatment of detached retinas looks like damage control and not welding in back on as described.
@Major Problems Thank you. So I was right? There's different procedures for welding the retina and the animation merely demonstrates how the detachment is prevented from progressing.
Bill, I love your rapid fire delivery. Don't change a thing! If I didn't catch something you said the first time around I can replay the video as many times as I need. This is the internet after all :-)
More videos please Bill! These are amazing.
Question: Why specifically Ruby? Do other corundum gems exhibit that same property?
I don't think it's the aluminum or oxygen in the corundum that actually gets pumped, but the chromium impurities. Other sapphires might be able to lase, but perhaps not in the visible spectrum, which is rather narrow?
Michael yes. my thoughts exactly... but you forgot to carry the 1.
@@jammccockin8304 😂
Bill the EngineerGuy vs. Bill Nye the Science Guy. They must fight in a cage!
A cage ... made of lasers!
Bill nye is also an engineer guy
Engineer fight! Someone break out the battlebot kits
The background music improves this enormously - thank you.
Feels like I'm watching Nova... or Modern Marvels. Super high production value, great job!
I learnt about how lasers work last year and he pretty much covered a weeks worth of lectures in this video. Basically, when the ruby is given enough energy an electron will be 'excited' into a higher energy state. when the electron drops energy state, energy is emitted in the form of light, thus laser. Hope that helps a bit.
Ok ..i found this channel yesterday and i watched like 20 videos
And i know nothing about these engineering
That was awesome. Now to watch it 20 more times so that I can follow it all.
I really enjoyed this video, Ill keep an eye for any more you share.
still no idea lol
I kept looking at the four red dots moving to the excited, lower energy and ground state, listening at his explanation and thinken: what on earth is he talking about and why dont these dots decide where they want to be?
+Tom Wesstein the dots go into the excited state because they're given energy from the outside light but they always go back to ground state by shooting out the energy as light because theyre lazy dots
+Tom Wesstein - Yes, make up your mind(s) already!
it's really basic quantum mechanics.
@@randominternetprofile8270 and?
Both mirrors have to be concave for this to work aka for the gaussisn optic to allow a mode
flat out wrong...
I can't stop watching your videos!
This is super amazing and with a nice fundamental explanation. Thanks
2:14 “lasing”
Wrong about "exact length of the rod". Length does not matter.
That's not what my wife said. Just before filing for divorce.
WildMania Correct, it's all about girth!
WildMania That's not what she said! lol
Awesome video - thanks for posting!
Bill, One of the most enjoyable channels on yt. And a voice of tranquility. 👍
but can you tear apart the Lazer pointer so we can see it.
Wait... I tought lasers don't need a lamp or a ruby. Was it an older version of a laser he was explaining?
TheArmFlailer
Never knew that. How come lasers are so cheap and affordable then? Are the gems impure or very small?
TheArmFlailer
Alright I see. Then what is the other laser with gas inside and no lamp? Only switching electron states?
TheArmFlailer
Oh ok. Thanks for explaining
There are many ways to make a laser. All you need is a laser cavity, a gain medium, and a source of energy. In the ruby laser, the flash lamp provides the 'pump' energy and the 'pumped' ruby provides the gain medium. Mirrors create the cavity. However, other things can be used as a gain medium. Helium neon lasers use a combination of helium and neon gas in a tube. Electricity passed through the tube provides the energy, the excited gas provides the gain, and the mirrors at the ends of the tube form the cavity. Diode lasers use specially doped semiconductor to form the gain medium with electric current providing the energy. The laser cavity can be formed a number of ways - cleaved semiconductor faces, distributed gratings, etc. Lasers can be used to pump gain material as well, for example erbium doped fiber amplifiers use lasers to pump energy into a section of glass optical fiber that contains a small amount of erbium to form the gain medium. This can be built into a laser, but more commonly it is used to amplify optical signals in a fiber so that they can be sent hundreds of miles. The gain medium can also be a liquid - lasers called dye lasers circulate liquid dye as a gain medium and can be pumped with flash lamps or other lasers to produce light with specific properties.
Alex Forencich
Yeah that's the type I was thinking about, like how do they make all the multi colored lasers. Thank you for explaining :)
You answer always questions I never asked myself before 😂
I've been through the laser treatment for retina thinning, not the most fun experience. Very cool to learn more about it!
Ruby rod? like that pop singer in 5th element?
136 people have been shot (and probably horribly disfigured) by lasers.
hmmm. is she at least 12? >_>
Where is she?
otacon333x2 I've never seen such an amount of sarcasm radiate through a comment.
manualLaborer so funny and original, how do you even come up with something like that
This is how the human penis erects! Upon seeing an attractive human, the eyes send a pleasure sensor to the brain, which instantaneously creates a surge of blood through the body's vein channels connected to the males testicles, resulting in an overflow of blood pulsating within a confined area of vessels. As this occurs, a rapid production of energy builds within the testicles producing millions of sperm! When the testicles become full, the sperms are released through the hole in the penis. Once all of the sperm is released, the energy relaxes to ground level, producingin a state of relaxation. The male then becomes very tired and falls asleep for several hours.
It's been said before, but it can never be said enough: your voice is beautiful.
Well done!! Good explanation of the energy states, just enough detail. Thank you!
engineerguy I recommend you to slow down while speaking to grasp the ideas you want to deliver ! Special thanks
+AbdulAziz AlHaidari - Yeah, the music implies that he's talking to 9-year-olds, but he's pouring information on the listener like they're a fellow engineer.
These videos are not that difficult to follow... but in any case, you guys know you can watch a video on TH-cam more than once, right?
+AbdulAziz AlHaidari I don't have any problem. You can turn on the Captions and/or slow down the video at the part what you couldn't understand.
Devo Castler As long as you've taken highschool science you'll get it
Yeah, he is a bit fast and I have to pause and read, but I prefer it that way rather than if he'd be too slow and make me lose patience, I would never watch his videos then :)
>scans his own book
shameless self promotion
Maybe he should scan yours
4 minutes ad.
C'mon, he is doing awesome work, I approve his ads.
Well done, articulate accurate and easy to understand, and you have a soothing voice.
awesome explanation! thank you for your excellent work on this
مين جى من عند محمود مجدي ☺️🤍🤍
هو انت بتزاكر الدرس قبل ما تاخده ولا ايه
Isn't it crazy that the same specie that is able to come up with stuff like this also engages in primitive behaviors such as chopping each other into pieces with machetes or blowing each other up with explosives? Usually for absolutely ridiculous reasons such as ethnicity, race or religion. It's staggering how smart and stupid humans can be at the same time.
That's due to differences between individual and collective behavior.
When I studied Engineering I just mugged it up without even understanding how it works, but your video is so simple and people can understand it. I have recommended my college and School to share the videos to the students to understand the stuffs. Thanks you so much for these educational videos. I would like to say Thanks in my Mother Tongue "நன்றி"
Amazing job, Bill. Thank you!
2:30 Good job at confusing the population there, why don't you show an atom instead? why don't you show electrons jumping from different energy levels and release photons?
This guy is great, but that hair of his could sure use some engineering.
+Pharaoh Polystyrene I think in the next video he will show how to do hairstyles like Albert Einstein, Donald Trump, Michael Jackson, Lagertha, Ragnar.. what kind of engineering stuff did the Vikings brought into English world to do a lot of hair styles.. probably will also discuss why Pharaohs hide his hairs under his hat, what kind of engineering did happen during Pharaohs era that the Nefertiti head become soooo biggggggg and hugeeeeeeeeeeee !!!
B. Smith I'm dying laughing.
B. Smith That loss of hair comes from a brain that works so hard there's no nutrients left for hair. Lol
B. Smith he must have stockpiled conditioner from the 80s.
B. Smith engineering xD nice expression :D :D
Ahhhh! Best channel on any media (for me). Can’t wait until he comes back with more. Thanks!
I’ve watched like every video, truly the people’s work. Bless you Sir
For nine years I've been missing out
*This is so well presented and fascinating to watch.*
Very informative. Thank you Engineerguy.
I would appreciate more information on the subject.This was laser 101. I would like to see expansions to your information. I know that ruby is not the main medium for lasers anymore, so I would love to see information on light spectrums, wavelengths, power, (etc) and how they tie into our modern lasers of today.
Oh I see! Thank you so much for the reply and all your videos!
Amazing as always. I got the book!
Dude this was amazing!
This is fascinating, I'd love to see a video like this describing how a Maser works.
That was an awesome video! I had no idea the first laser was made with a ruby
Amazing presentation!
I've always wanted to know this. Thank you so much !
Nice simple explanation. Really good.
Thank you very much for the video!
he can have what ever hair cut he wants, this guy's a weapon. Thanks for sharing your knowledge Bill.
Great explanation of "ruby". Thanks.
Esto es lo que siempre estuve buscando, Gracias
*I wish you made longer 30 min videos going more in depth you are so good at explaining things want to learn more*