*I am using the conventions of circular polarisation according to electrical engineering , not the one used in optics*(adsbygoogle = window.adsbygoogle || []).push({});

Let us take a uniform plane TEM wave travelling in +z direction which is composed of two linearly polarised TEM waves , one whose electric field lies in X direction , the other whose electric field lies in Y direction . Let us take the case of circular polarisation

so we take ,

E_{x}= E_{0}cos([tex]\omega[/tex] t - [tex]\beta[/tex] z) a_{x}

E_{y}= E_{0}cos([tex]\omega[/tex] t - [tex]\beta[/tex] z + [tex]\pi[/tex]\2) a_{y}

Now the resultant TEM wave has the Electric field vector left handed circularly polarised .

On the Poincare Sphere this will be given by the north pole point.

Suppose we had same wave ,but travelling in -ve z direction.

E_{x}= E_{0}cos([tex]\omega[/tex] t + [tex]\beta[/tex] z) a_{x}

E_{y}= E_{0}cos([tex]\omega[/tex] t + [tex]\beta[/tex] z + [tex]\pi[/tex]\2) a_{y}

My doubt is :- is the wave left handed circularly polarised or right handed circularly polarised ? And where on Poincare sphere is it located?

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# How does Poincare sphere for a TEM wave depend on direction of propagation of wave?

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