Semi major and minor axis of polarization ellipse

AI Thread Summary
The discussion focuses on deriving the equations for the semi-major and semi-minor axes of the polarization ellipse. The initial approach involves manipulating equations related to electric field components and applying trigonometric identities. A rotation matrix is suggested for relating the axes, but there is a challenge in incorporating the cosine term into the final results. The participant expresses uncertainty about achieving the correct answer without the necessary cosine component. Assistance is sought to resolve this issue in the derivation process.
henil
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how can he we derive equations for semi major and minor axes of the polarization ellipse?
 
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From what?
 
Use these equations
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to derive this equations
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I just thought of one delta as dy-dx so only one of the first 2 equations actually has a delta in it
Rearranged one of the first equations, the one that no longer has a delta in it, for Ex/Ax=cos(wt-kz)

I then used a few trig identities on the second equation
oqrQ6j7.jpg
SKSqITC.jpg

squared the result then substituted the rearranged equation 1 into the cos(wt-kz) spot and the cos2(wt-kz) spot to get equation 3

Now to derive these equations from the result which are the semi major axis and semi minor axis
5dFsnjb.jpg

just use a rotation martix
3UDrLYX.jpg

where x'=a, y'=b, x=Ax, y=Ay and square each component

This is where I am stuck as I do not have the cos(delta) in the final answer so anyone that knows better can help you (and me) with the correct answer
 

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