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1

The electric component of an electromagnetic plane wave can oscillate in

any direction normal to the direction of wave propagation (which is parallel to the k vector)

2

A represents

Electric field

3

B represents 

Magnetic field

4

Suppose that the wave is propagating in the z direction. It follows that the

electric field can oscillate in any direction that lies in the x - y plane

5

The actual direction of oscillation determines the

polarization of the wave

6

The actual direction of oscillation determines the polarization of the wave. For instance,

a vacuum electromagnetic wave of angular frequency ω that is polarized in x direction has the associated electric field

 

7

a vacuum electromagnetic wave of angular frequency ω that is polarized in x direction has the associated electric field. 

where ω=

ω=kc

8

where ω=kc. Likewise, a wave polarized in the y direction has the electric field

9

A represents

Horizontal linear polarization

10

B represent

Vertical linear polarization

11

Vertically polarized wave

is one for which the electric field lies only in the x-z plane

12

Horizontally polarized wave

is one for which the elecric field lies only in the y-z plane

13

(Vertical and horizontal polarized wave )These two waves are termed __________________

linearly polarized

14

These two waves are termed linearly polarized, since the

electric field vector oscillates in a straight-line

15

These two waves are termed linearly polarized, since the electric field vector oscillates in a straight-line. However,

other types of polarization are possible

16

, other types of polarization are possible. For instance, if we combine

two linearly polarized waves of equal amplitude, one polarized in the x direction, and one in the y direction, that oscillate π/2 radians out of phase, then we obtain a circularly polarized wave:

17

a circularly polarized wave

18

A represents

Left hand circular polarization

19

B represents

Right hand circular polarization

20

if the x and y components of the electric field in the previous two expressions have different ____________________ then we

(non-zero) amplitudes then we obtain right-hand and left-hand elliptically polarized waves, respectively.

21

(non-zero) amplitudes then we obtain right-hand and left-hand elliptically polarized waves, respectively. This nomenclature arises from

the fact that the tip of the electric field vector traces out an ellipse in the plane normal to the direction of wave propagation.

22

A represents 

Linear

23

B represents

Circular

24

C represents

Elliptical

25

The Stokes parameters are

a set of values that describe the polarization state of electromagnetic radiation.

26

The Stokes parameters are a set of values that describe the polarization state of electromagnetic radiation. They were defined by George Gabriel Stokes in 1852, as a

mathematically convenient alternative to the more common description of incoherent or partially polarized radiation

27

a mathematically convenient alternative to the more common description of incoherent or partially polarized radiation in terms of

its total intensity (I), (fractional) degree of polarization (p), and the shape parameters of the polarization ellipse.

28

The Stokes parameters are often combined into

a vector, known as the Stokes vector:

29

Stokes Vector consists of four parameters (called Stokes parameters):

intensity I,

the degree of polarization Q,

the plane of polarization U,

the ellipticity V.

30

Stokes parmeters in terms of intensities

I = total intensity
Q= I0-I90 = differences in intensities between horizontal and vertical linearly polarized components;
U = I+45 –I-45= differences in intensities between linearly polarized  components oriented at +45 and -45
V = Ircl –Ilcr= differences in intensities between right and left circular polarized components.