How Lasers Work (in practice) – Smarter Every Day 33

December 4, 2011 by 42 Comments

Click to see the Minute Physics take on Lasers:
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Johan has a website! He makes lasers! :

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42 Replies to “How Lasers Work (in practice) – Smarter Every Day 33”

  1. That guy has to smoke a lot of weed

  2. So how does a laser work?

  3. Kavin Raj says:

    please explain working video

  4. what an appropriate shirt ! thanx so much for explaining !

  5. trash man says:

    Is this at Delft by chance?

  6. Photon torpedoes are STAR TREK!!

  7. Jack Nedry says:


  8. Hey SmarterEveryDay from Nepal! Love your videos and have been watching a lot of your videos lately. I am getting Smarter with every video of yours. I have a question and it might be stupid but here goes… The light is being reflected back and forth using the mirrors that are facing each others right. If the mirrors were 100% reflective (No loss at all) and we removed the source of light, what would happen? Will the light still remain since the light is being reflected back and forth? Again, this might be stupid question… Thank you for the awesome videos.

  9. I just watched to guys play with Light Amplification by Stimulated Emission by Radiation for 4 minutes……….why

  10. Arslan Kabir says:

    Are you retired from air force as a pilot?

  11. Ben Ghist says:

    Did he just point at a star wars shirt and say photon torpedo…

  12. JC Vela says:

    Hey thanks. What is the laservision goggle's price? What model is that? F18P1B05?

  13. Lola Lola says:

    You need to start using mics for your vids -.- awesome videos tho <3

  14. Ivan Budaev says:

    Thank you for Russians subtitles!

  15. I always thought that lasers worked by pushing energy into atoms inside a semi-silvered capsule to the point that the outermost electron becomes excited to the point that it jumps out to the next electron shell, then immediately releasing the excess energy by releasing a photon and falling back into its original electron shell. I thought that these photons bounced around in all directions in the semi-silvered capsule until they met the semi-silvered end caps of the capsule at the correct angle so that the photons could pass through, to create a laser beam.

  16. My avast antivirus blocked the link at the end of video as virus O_o

  17. Donny Estee says:

    This guy breathes Dutch

  18. Masta Blasta says:

    Today I learned that LASER is an acronym for Light Amplification by Stimulated Emission of Radiation.

  19. Smarter everyday dutch hier suriname 😆

  20. Laurelindo says:

    This video is relevant for sections 15.1 and 15.2 in the book "Fundamentals Of Photonics, Second Edition" in my course "Optics & Photonics" at LTU in Sweden.

    I am pointing that out here as a reminder in case I forget, lolz.

  21. Steve Waclo says:

    A another rare example of a phenomenon that does not exist in nature, but has been produced by the human mind! Hey, we are pretty special.

  22. Hey its me destin being chill at uranus with my alien buddy jakasmdmdks today we are going to learn about dark energy’s origin

  23. This was one of my lab experiment last year, and it's super hard to get the mirrors perfectly aligned, I never get the laser working.

  24. Dino Luj says:

    3:33 contains picture for a blink of an eye .

  25. Johan made a Hilarious correction to Destin putting Star Trek properly superior for credence to that other one which shall remain nameless. Destin, you were improperly dressed today. Tsk Tsk! 🤓 Trek On Boundless!

  26. jalal kurdi says:


  27. You should do a collab with channel Styropyro here on YouTube

  28. Paul Stovall says:

    So it's my understanding that the light energy bounces back and forth between the two mirrors (one being just less reflective than the other) until the beam breaks through the less reflective mirror which results in beam emission. That tells me that there is a substantial energy loss. Most of the power remains inside the open cavity tube allowing only a lesser percentage of the power to escape.
    We have auto reactive welding masks the lenses of which are transparent until the goggles detect the higher light energy emitted by arc action. The lenses of the goggles automatically darken to protect the welders' eyes, then return to transparent once the more intense light ceases.
    Would there be any way to create an auto response mirrored surface that would react in similar fashion? With such a mirrored surface, the two mirrors (one being a stable full reflective mirror at the back end of the laser) could be made completely reflective until such time as beam emission was desired allowing for full power emission instead of partial.

  29. Devious rj says:

    Hey buddy can you tell me where I can buy this kind of laser and mirrors ????

  30. I remember batfleck laser.

  31. NS Gaming says:

    anyone in 2020 ???

  32. what kind of laser technology is used on laser weapons ? This neon,helium is appropriate ?

  33. Vincent Kwok says:

    He was already quite good from the start.

  34. Limbslap says:

    he got a lot smarter from this video to 2020

  35. Hello my friends , my name is Leonidas, I am from Brazil, I have been reading and studying about co2 laser tubes for a year, I have read more than 20 articles, even from NASA, I bought books on Amazon, but unfortunately I cannot recondition a laser tube, something is missing something I don't know what it is.
    I need help from someone in the group who can help me, I am on the other side of the planet, I would not disturb anyone's business, I just want to learn.
    What CO2 laser catalyst do I find to buy?
    There is a secret of the aging of the gas in the laser tube in its decay can someone explain to me how to do it?
    About the vacuum pumps for filling the tube, which is the best?
    what are the best suppliers you know?

  36. Johan? Naoki Urasawa's "Monster?"

  37. Dude, in every video he is in a different place.

  38. Mary Lagua says:

    You must have understood what he said in Dutch very impressive.

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