PhD Thesis

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METU - NCC
EEE 303 ELECTROMAGNETIC WAVESEM Movies
Dr. Özlem ÖZGÜN
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Wave Types
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Introduction to Waves
This animation shows a simplest solution for
Ex(z,t) of the one-dimensional wave equation
as a function of space and time, namely,
Riding the Wave
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Plane Waves
Wave Propagation in Free Space
CLICK ME
Circularly polarized Plane Wave
Linearly polarized Plane wave
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Polarization
Polarization is a description of how the
direction of the electric field vector changes
with time at a fixed point in space. If the wave
is propagating in the positive z-direction, the
electric field vector at a fixed point, say z0,
can be expressed in the following general form
Then, the polarization can be categorized using
the two real quantities A and ?.
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Polarization
Linear polarization For A 0, the electric
field vector has only the x-component. The tip
of the electric field vector traces a line as
time advances.
3D view
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Polarization
Linear polarization A 1, ?0 The x- and
y-components of the electric field have the same
magnitude and are oscillating in phase. The tip
of the total electric field vector still traces a
line.
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Polarization
Linear polarization A 2, ?0 The
y-component of the electric field is twice
stronger than the x-component. However, since
they oscillate in-phase, the polarization remains
linear.
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Polarization
Left hand circular polarization A 1, ? pi/2
The x- and y-components of the electric field
have the same magnitude and are oscillating 90?
out-of-phase. The tip of the total electric field
vector traces a perfect circle.
3D view
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Polarization
Right hand circular polarization A 1, ?
-pi/2 The x- and y-components of the electric
field have the same magnitude and are oscillating
90? out-of-phase (but opposite to the LHCP
situation)
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Polarization
Right hand elliptical polarization A 2, ?
-pi/2 The y-component is twice as strong as the
x-component. The two components are oscillating
90? out-of-phase. The polarization ellipse is
vertically elongated.
3D view
CLICK ME
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Polarization
Left hand elliptical polarization A 1, ?
pi/4 The x- and y-components of the electric
field have the same magnitude but are oscillating
45? out-of-phase, which makes it elliptically
polarized instead of circularly or linear.
3D view
CLICK ME
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Reflection and Transmission
The following animation sequences illustrate the
reflection and transmission of a plane wave at a
planar interface between two dielectric media
characterized by (?1, ?1) and (?2, ?2),
respectively.
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Reflection and Transmission
Less Dense Medium to Denser Medium
(?1, ?1) (?0, ?0) (?2, ?2) (4?0, ?0)
Only incident and transmitted wave (no reflected
wave)
Incident, transmitted and reflected waves)
With the reflection included, one can visualize
the interference pattern between the incidence
and the reflection
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Reflection and Transmission
Denser Medium to Less Dense Medium
(?1, ?1) (4?0, ?0) (?2, ?2) (?0, ?0)
Only incident and transmitted wave (no reflected
wave)
Incident, transmitted and reflected waves)
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Reflection and Transmission
Denser Medium to Less Dense Medium
(?1, ?1) (4?0, ?0) (?2, ?2) (?0, ?0)
The angle of incidence is exactly at the critical
angle.
TOTAL REFLECTION
The evanescent surface wave in the lower half
space can be visualized
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Reflection and Transmission
Denser Medium to Less Dense Medium
(?1, ?1) (4?0, ?0) (?2, ?2) (?0, ?0)
This sequence shows a snap-shot of the waves at a
fixed time for different angles of incidence.
One can visualize the transition from the
regular reflection cases when the incidence angle
is smaller than the critical angle to the
frustrated total internal reflection cases when
the incidence angle is larger than the critical
angle.