Introduction to polarization of light, polarizing filters, polarization by reflection and scattering

[@michaellovejoy8751]

First video I found that actually explains the mechanism (ie. in the context of oscillating dipoles). Makes total sense!

[@ZaksLab]

Thanks! - Zak

[@kunalsadana6131]

Such a beautiful explanation. First video where it is clearly mentioned about oscillating dipoles and how that influences the vibration of light particles.

[@ZaksLab]

Thank you! -- Zak

[@how-about-no_56]

I studied this a month ago and forgot the explanation our professor gave. This is the only video that explains the mechanism behind it. Thanks for making this video. Love from Bharat

[@ZaksLab]

glad I could help! z

[@parsoakhorsandmusic]

Great video. Thanks!

[@ZaksLab]

you're welcome! z

[@GuitarJ111]

Dude amazing video, great thorough explanation

[@ZaksLab]

Thanks! -- Zak

[@klevisimeri607]

Beautiful! Amazing Job!

[@ZaksLab]

Thanks! -- Zak

[@6l816]

3:43 "molecules at the point of contact are oscillating back and force with this orientation" Why that orientation and not others?

[@ZaksLab]

Both components are there - in and out of the page, and the other component that I highlighted. Linear combinations of these two components give you all possible orientations of electric field perpendicular to the direction of motion (light is a transverse wave). Then the point is that the component shown in the page cannot radiate in the direction of oscillation, so that component is killed off, leaving only the "in and out of the page component". Hope this helps. z

[@levmilarlpvp]

Can someone explain why the reflection off of a vertical surface results in vertical polarization? You can turn the picture 90° and then you will be left with the horizontally oscillating part (the part that goes into the plane), so nothing should change. ?

[@levmilarlpvp]

ok I got it, it will be vertically polarized if the light comes from the side (if it is parallel to the horizon). If it comes from the top, it will be horizontally polarized

[@christianjourneytv1003]

Thanks.

[@ZaksLab]

You're welcome!

[@HabibUrRahman-sr2wn]

One thing which is confusing is what exactly you mean by vertical polarization and horizontal polarization Is it something to do with these dots and arrows? Or do you mean to say that every point in reflected ray has horizontal and vertical component with one being on the surface of glass and other vertical respectively?

[@ZaksLab]

dot = component of polarization oscillating perpendicular to the page, arrow = component of polarization oscillating in the plane of the page, and both components of polarization oscillate perpendicular to the direction of the ray propagation

[@nowthenad3286]

When I have seen other people explaining this they draw lines on the polarization material that are parallel with the polarization axis. Why have you drawn it differently?

[@ZaksLab]

I see -- you were refering to the polarizing film! Yeah, the actual physical chains of molecules are responsible for killing off E field because of currents that run parallel through those chains. So those lines represent the actual chains of molecules and the surviving light is *perpendicular* to that axis. In many diagrams, they just show lines in the direction of polarization as if the waves are passing through slots in a picket fence, but those lines are actually perpendicular to the molecular structure in the film! Maybe it's a useful tool for visualization, but it causes confusion about what's actually going on at the micro level, which is essentially the opposite of the typical diagram. One polarization is killed off precisely because we have conductive chains whose electrons can respond to the E field in that direction; i.e., the direction in which electrons can actually move is the direction in which energy is absorbed and the polarization is killed off. z

[@nowthenad3286]

@@ZaksLab Thank you very much for taking the time to reply. A very clear explanation as well.

[@ZaksLab]

@@nowthenad3286 you're welcome! z

[@herbertauer434]

When light gets reflected at the Brewer´s angle, it gets polarized. What does happen to the part the enters glass or water? Does it get enriched for the other direction(s)?

[@ZaksLab]

Really good question! With the horizontal polarization reflected off the surface, the percent horizontal in the refracted ray is reduced relative to the vertical polarization, since all the vertical polarization is refracted. It's one thing I forgot to get into the diagram (normally illustrated by showing half as many dots in the refracted ray for example). -- Zak

[@II-th7bn]

Keep it up 👍👍 ❤️ from India

[@ZaksLab]

Thanks! -- Zak