How a Laser Works 

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 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.

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

Wow hello there

Last place Id expect to see him

@@silkwurms same

It's the haircut.

why is this true

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.

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

Its been Seven years, How's Your book coming?

At the publisher now!

@@engineerguyvideo bill please make more 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.

Totally reminds me of FilmmakerIQ

Could you please give me a definition of a professional fuck?

Prostitution?

A. Goraya lol

Unlike you

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

engineer gaming

@@ft_lesserchungus1192 engineer gaming

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

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.

+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

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 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

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

lmao! dude, you nailed it!

Sad. Probably murdered, God rest his soul. 🙏🌹

I can't find any information on his son.

@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.

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 😂

+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....

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 .

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.

Crazy how they had that technology back in the 70s

A cage ... made of lasers!

Bill nye is also an engineer guy

Engineer fight! Someone break out the battlebot kits

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?

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

flat out wrong...

Wow 10 inch long in last 10 years

+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 RU-vid 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 :)

Spoon Thief I think it was sped up. Hello from the Future

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 :)

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.

That's due to differences between individual and collective behavior.

+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

هو انت بتزاكر الدرس قبل ما تاخده ولا ايه