1. ELECTROMAGNETIC WAVE PROPAGATION Polarization
Fields and Waves
Lesson 5.4
ELECTROMAGNETIC WAVE PROPAGATION
Polarization
Lale T. Ergene

2. Wave Polarization
describes the shape and locus of tip of the vector at a given point in space as a function of time
The locus of , may have three different polarization states depends on conditions
Linear
Circular
Elliptical

3. Polarization
For a +z-propagating wave, there are two possible directions of
Direction of is called as polarization
They are two independent solution for the wave equation
Linear combinations make all possibilities

4. Ey0=ayejδ ax,ay are the magnitudes of Ex0 and Ey0
Polarization
a uniform plane wave traveling in the +z direction may have x and y components
Complex amplitudes
The phase difference between the complex amplitudes of x and y components of electric field can be defines with angle δ
Ex0=ax
Ey0=ayejδ ax,ay are the magnitudes of Ex0 and Ey0

5. Polarization The phasor of electric field
The corresponding instantaneous field

6. Intensity and Inclination Angle
The intensity of
The inclination angle ψ
generally they both are function of t and z

7. Linear Polarization E +z B
Can make any angle from the horizontal and vertical waves

8. Linear Polarization A wave is said to be linearly polarized if and
Are in phase (δ=0) or out of phase (δ=π)
In phase
Out of phase

9. Linear Polarization (out of phase)

10. Linear Polarization Looking up from +z
x-polarized or horizontal polarized
ay= ψ=0° or °
y-polarized or vertical polarized
ax= ψ=90° or °

11. Circular Polarization
A wave is said to be circularly polarized if
the magnitudes of and are equal and
The phase difference is δ=±π/2
δ=π/2
δ=-π/2

12. Elliptical Polarization
Generally ax≠ay≠0 and δ≠0. the tip of traces an elliptical path in x-y plane
rotation angle, γ
-π/2≤γ≤π/2
Ellipticity angle, χ
-π/4≤χ≤π/4

13. Polarization states The wave is traveling out of the slide
Do problem 1&2