Lecture -- Wave Polarization

This video explains polarization of electromagnetic waves in a very visual manner. Visualizations are presented along side mathematical equations to help the student understand polarization and to determine the polarization of a wave.

[@flaxenkj]

Fantastic explanations on all (wave) fronts. Thank you for making and sharing this.

[@naumanshafique1745]

A succinct and intuitive explanation. The graphics used are really helpful throughout the video to validate the concepts.

[@phildrumfish2391]

The animations are just great. It really helps understanding the principle. Better explained as in every book i had so far !

[@empossible1577]

Thank you!!

[@fuzzyelectrons]

Excellent description. The animations were very well done and all the derivations were clear. Hats off!

[@razanhamed2569]

This is super helpful! Thank you!

[@ccCLASICUSss]

Totally Perfect! Thank you!

[@localfuture1484]

Hi, I am afrid there is something wrong with the table at 37:36. For a + jb, I think it's left-hand circularly polarized (LHCP) and for a-jb, it's right-hand circularly polarized. For example, (a+jb) * (cos(wt) + j sin(wt)), it's real part is cos(wt) a - sin(wt) b , this will circular clock-wise (if we use thumb pointing at Z direction, it's left-hand cicularly polarized). You may check "MICROWAVE ENGINEERING" DAVID M. POZARD, in that book, +90degree is LHCP. Maybe the inconsistence is due to some "convention". Could you double check and help clarify it?

[@empossible1577]

You are right! It turns out due to sign convention, the answer is opposite for engineers and scientists. I am using the negative sign convention here (more common for engineers) but I guess was thinking positive sign convention. will fix this ASAP! Thank you!!

[@hytham1026]

you are good

[@empossible1577]

Thank you! Happy to help!

[@fatihtutar3465]

Perfect animation and explanation thank you so much

[@empossible1577]

Thank you!

[@Kratorxxx58]

In the last slide (46:25) the polarization vector P is not perpendicular to the wave vector k... but in an EM plane wave the electric field is always perpendicular to the direction of the wave propagation.

[@empossible1577]

Ha ha! You are right! How did I goof on that!?!?

[@acg6350]

This video was amazing. Thank you.

[@empossible1577]

Thank you!!! I appreciate the feedback. For a long time, the video I had on polarization was horrible. Maybe 1.5 years ago I completely revised that section. I may not be 100% happy with it yet, but it is lot better than what I used to have!

[@acg6350]

@@empossible1577 The animations were on point. I especially loved the visualization of the Poincaré sphere. I was struggling to see how a polarization state was a point on the sphere, but it came all together with that one.

[@empossible1577]

@@acg6350 That is great to hear!

[@mauriciodias458]

Excellent video, as usual. However, the determination of the sense of rotation of the circular polarization seemed to me to be reversed, since the sign convention is that of engineering. Following Balanis' walkthrough, for example, for RH polarization delta should be -90 instead of 90, and vice-versa.

[@mauriciodias458]

For instance, if we take E=âx cos(wt - kz) + ây cos(wt - kz + delta), with delta =+90, and fix z=0, at wt=0 we have E=âx, and at wt =90o we have E=ây*(-1), thus leading to LH polarization, when we see the wave forward propagating along +z.

[@localfuture1484]

Hi 26:09, the blue portion of the formula seems not so correct. It should be [(1+cosθ + jsinθ) ax + (sinθ - j cosθ + j) ay]. For example, when θ=0，the original formula isn't correct (there should be 2 ax instead of 1 ax).

[@empossible1577]

A few mistakes have been caught in this video. I will go through this in detail and make all necessary corrections. Thank you!

[@localfuture1484]

I Think for final slide, the unit for k should be rad/m instead of 1/m due to the absence of 2pi.

[@localfuture1484]

Am I right?

[@empossible1577]

The units are rad/m for sure. However, it is also proper to not write the rad unit sometimes. I seem to have included it for omega, but not for k. While the slide is not wrong, it is certainly inconsistent and therefore confusing. Sorry!

[@localfuture1484]

@@empossible1577 Got it. Understand that.

[@meghjitmajumder3468]

1. Is circular polarization also confined to a plane? 2. Can't find suitable words to appreciate your works...Thanks Sir

[@empossible1577]

Thank you!! All polarizations in linear, homogeneous and isotropic (LHI) media are confined to a plane that is perpendicular to the direction of propagation. Linear polarization is further confined to a single axis, but circular polarization is essentially just two linear polarizations along perpendicular axes.

[@meghjitmajumder3468]

The last two slides are just excellent!! Especially the penultimate one..