What can a rainbow tell us about the limits of focusing a laser? Focusing a laser beam into a tiny spot is important in many technologies. In this video I will go through two examples: optical discs like CDs, DVDs and Blu-rays as well as laser engravers. Does the wavelength of the laser matter? Let's find out!

Thank you very much to Edwin En-Te Hwu and Anja Boisen for letting me use their illustration!
Link to their publication with even more, interesting info: https://pubs.acs.org/doi/10.10....21/acssensors.8b0034
Edwin Hwu's channel: https://www.youtube.com/c/Edwi....nHwuHacks4Science/vi

Laser engraver Aufero Laser 1 and accessories donated by Ortur: https://www.aliexpress.com/ite....m/1005003346728741.h

Why does light bend? (Fermilab): https://www.youtube.com/watch?v=NLmpNM0sgYk
Why does light slow down (Fermilab): https://www.youtube.com/watch?v=CUjt36SD3h8
Calculate photon energy: https://www.omnicalculator.com..../physics/photon-ener
Calculate focus spot size: https://wavelength-oe.com/opti....cal-calculators/focu
Calculate depth of focus: https://wavelength-oe.com/opti....cal-calculators/dept

My Patreon-page: https://www.patreon.com/Brainiac75
Make your own laser beam dump: https://youtu.be/rRIlhskMYAM
My strongest laser, 5W laser vs. 5W LED: https://youtu.be/vUwP7SY0Ajs
Did you miss one of my videos?: https://www.youtube.com/user/brainiac75/videos

FULL MUSIC CREDITS
Time code: 0:01
"Fluidscape" Kevin MacLeod (incompetech.com)
ISRC: USUAN1100393

Time codes: 0:41 + 7:36 + 8:57
"Lightless Dawn" Kevin MacLeod (incompetech.com)
ISRC: USUAN1100655

Time codes: 3:21 + 5:00
"Darkness is Coming" Kevin MacLeod (incompetech.com)
ISRC: USUAN1100584
(Looped by me)

Time code: 4:19
"Impact Lento" Kevin MacLeod (incompetech.com)
ISRC: USUAN1100619

Time code: 4:46
"Ossuary 6 - Air" by Kevin MacLeod (incompetech.com)
ISRC: USUAN1500048

Time code: 6:41
"Light Awash" Kevin MacLeod (incompetech.com)
ISRC: USUAN1100175

Time code: 9:29
"Adding the Sun" Kevin MacLeod (incompetech.com)
ISRC: USUAN1900041

All music above licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

Time code: 8:28
Mix of two tracks:
1) The Shimmering by fran_ky (freesound.org/s/237363)
Licensed under Creative Commons 0 license
2) "Spacial Harvest" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/
ISRC: USUAN1100653

#Laser #Rainbow #Brainiac75