Describes the propagation of electromagnetic waves in anisotropic electrical media.
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2. 2
Maxwell Equations & Propagation in Anisotropic MediaSOLO
TABLE OF CONTENT
Maxwell’s Equations
History of Maxwell’s Equations
Symmetric Maxwell’s Equations
Constitutive Relation
Boundary Conditions
Energy and Momentum
Monochromatic Planar Wave Equations
Planar Waves in an Source-less Anisotropic Electric Media
Lorentz’s Lemma
Planar Wave Group Velocity
Phase Velocity, Energy (Ray) Velocity for Planar Waves
Energy Flux and Poynting Vector
Energy Flux and Poynting Vector for a Bianisotropic Medium
Wave equation
Wave-Vector Surface
Double Refraction at a Uniaxial Crystal Boundary
Refractive Index of Some Typical Crystals
Polarization History
3. 3
Maxwell Equations & Propagation in Anisotropic MediaSOLO
TABLE OF CONTENT
Planar Waves in an Source-less Anisotropic Electric Media
Orthogonality Properties of the Eigenmodes
Phase Velocity, Energy (Ray) Velocity for Planar Waves
Ray-Velocity Surface
Index Ellipsoid
Conical Refraction on the Optical Axis
Equation of Wave Normal
References
4. 4
POLARIZATION
Erasmus Bartholinus,doctor of medicine and professor of
mathematics at the University of Copenhagen, showed in 1669 that
crystals of “Iceland spar” (which we now call calcite, CaCO3)
produced two refracted rays from a single incident beam. One ray,
the “ordinary ray”, followed Snell’s law, while the other, the
“extraordinary ray”, was not always even in the plan of incidence.
SOLO
History
Erasmus Bartholinus
1625-1698
http://www.polarization.com/history/history.html
5. 5
POLARIZATIONSOLO
History
Étienne Louis Malus
1775-1812
Etienne Louis Malus, military engineer and captain in the army of
Napoleon, published in 1809 the Malus Law of irradiance through a
Linear polarizer: I(θ)=I(0) cos2
θ. In 1810 he won the French Academy
Prize with the discovery that reflected and scattered light also possessed
“sidedness” which he called “polarization”.
6. 6
POLARIZATION
Arago and Fresnel investigated the interference of
polarized rays of light and found in 1816 that two
rays polarized at right angles to each other never
interface.
SOLO
History (continue)
Dominique François
Jean Arago
1786-1853
Augustin Jean
Fresnel
1788-1827
Arago relayed to Thomas Young in London the results
of the experiment he had performed with Fresnel. This
stimulate Young to propose in 1817 that the oscillations
in the optical wave where transverse, or perpendicular
to the direction of propagation, and not longitudinal as
every proponent of wave theory believed. Thomas Young
1773-1829
8. 8
POLARIZATIONSOLO
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
Methods of Achieving Polarization
Polarization by Birefrigerence (continue – 1)
Polarization can be achieved with crystalline materials which have a different index of
refraction in different planes. Such materials are said to be birefringent or doubly refracting.
Nicol Prism
The Nicol Prism (1828) is made
up from two prisms of calcite
cemented with Canada balsam.
The ordinary ray can be made to
totally reflect off the prism
boundary, leving only the
extraordinary ray.
William Nicol(1768 ?– 1851) Scottish physicist
9. 9
POLARIZATIONSOLO
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
Methods of Achieving Polarization
Polarization by Birefrigerence (continue – 2)
Polarization can be achieved with crystalline materials which have a different index of
refraction in different planes. Such materials are said to be birefringent or doubly refracting.
Wollaston Prism
William Hyde
Wollaston
1766-1828
13. 13
MAXWELL’s EQUATIONSSOLO
Magnetic Field IntensityH
[ ]1−
⋅mA
Electric DisplacementD
[ ]2−
⋅⋅ msA
Electric Field IntensityE
[ ]1−
⋅mV
Magnetic InductionB
[ ]2−
⋅⋅ msV
Current DensityJ
[ ]2−
⋅mA
Free Charge Distributionρ [ ]3−
⋅⋅ msA
James Clerk Maxwell
(1831-1879)
A Dynamic Theory of Electromagnetic Field 1864
Treatise on Electricity and Magnetism 1874
Return to Table of Content
14. 14
SOLO
Electrostatics
Charles-Augustin de Coulomb
1736 - 1806
In 1785 Coulomb presented his three reports on Electricity and
Magnetism:
-Premier Mémoire sur l’Electricité et le Magnétisme [2]. In this
publication Coulomb describes “How to construct and use an
electric balance (torsion balance) based on the property of the
metal wires of having a reaction torsion force proportional to the
torsion angle”. Coulomb also experimentally determined the law
that explains how “two bodies electrified of the same kind of
Electricity exert on each other”.
-Sécond Mémoire sur l’Electricité et le Magnétisme [3]. In this
publication Coulomb carries out the “determination according to
which laws both the Magnetic and the Electric fluids act, either
by repulsion or by attraction”.
-Troisième Mémoire sur l’Electricité et le Magnétisme [4]. “On
the quantity of Electricity that an isolated body loses in a certain
time period , either by contact with less humid air, or in the
supports more or less idio-electric”.
15. 15
SOLO
Electrostatics
Charles-Augustin de Coulomb
1736 - 1806
1 2
12 123
0 12
1
4
q q
F r
rπ ε
=
Coulomb’s Law
q1 – electric charge located at 1r
q2 – electric charge located at 2r
12 1 2r r r= −
The electric force that the charge
q2 exerts on q1 is given by:
If the two electrical charges have the same sign the force is
repulsive, if they have opposite signs is attractive.
12
0 8.854187817 10 /Farad mε −
= ×Permittivity of
vacuum
Accord to the Third Newton Law of mechanics: 21 12F F= −
12 1 12F q E=
Define 2
12 123
0 12
1
4
q
E r
rπ ε
=
where is the Electric Field Intensity [N/C]
16. 16
SOLO
During an evening lecture in April 1820, Ørsted discovered
experimental evidence of the relationship between electricity
and magnetism. While he was preparing an experiment for one
of his classes, he discovered something that surprised him. In
Oersted's time, scientists had tried to find some link between
electricity and magnets, but had failed. It was believed that
electricity and magnetism were not related. As Oersted was
setting up his materials, he brought a compass close to a live
electrical wire and the needle on the compass jumped and
pointed to the wire. Oersted was surprised so he repeated the
experiemnt several times. Each time the needle jumped toward
the wire. This phenomenon had been first discovered by the
Italian jurist Gian Domenico Romagnosi in 1802, but his
announcement was ignored.
1820Electromagnetism
Hans Christian Ørsted
1777- 1851
17. 17
SOLO
1820Electromagnetism
André-Marie Ampère
1775 - 1836
Danish physicist Hans Christian Ørsted's discovered in 1820 that a
magnetic needle is deflected when the current in a nearby wire varies -
a phenomenon establishing a relationship between electricity and
magnetism. Ørsted's work was reported the Academy in Paris on 4
September 1820 by Arago and a week later Arago repeated Ørsted's
experiment at an Academy meeting. Ampère demonstrated various
magnetic / electrical effects to the Academy over the next weeks and he
had discovered electrodynamical forces between linear wires before the
end of September. He spoke on his law of addition of electrodynamical
forces at the Academy on 6 November 1820 and on the symmetry
principle in the following month. Ampère wrote up the work he had
described to the Academy with remarkable speed and it was published in
the Annales de Chimie et de Physique.
Ampère and Arago
investigate magnetism
dl
uu
an infinitesimal element of the contour C
J
curent density A/m2
dS
uu
a differential vector area of the surface S enclosed by contour C
Ampère’s Law
Magnetic Field IntensityH
[ ]1−
⋅mA
18. 18
SOLO
1820
Electromagnetism
Biot-Savart Law
0
2
1
4
rI dL
dB
r
µ
π
×
=
uu u
uu
Magnetic Field of a current element
Jean-Baptiste Biot
1774-1862
( )( )
1
1 2
21 1 1 21
1 2 1 20
1 2 3
1 2
4
c
c c
F I dl B
dl dl r r
I I
r r
µ
π
= ×
× × −
=
−
∫
∫∫
uu
uu uu
Ampère was not the only one to react quickly
to Arago's report of Orsted's experiment. Biot,
with his assistant Savart, also quickly conducted
experiments and reported to the Academy in
October 1820. This led to the Biot-Savart Law.
Félix Savart
1791 - 1841
19. 19
SOLO
1820
Electromagnetism
Biot-Savart Law
Jean-Baptiste Biot
1774-1862
( )
( )2 30
0
'
'
4 '
J r
A J A r d r
r r
µ
µ
π
∇ = − ⇒ =
−∫
0
0
H J B H
B B A
µ∇× = =
∇× = → = ∇×
( ) ( ) 2
0B A A A Jµ∇× = ∇× ∇× = ∇ ∇× −∇ =
choose 0A∇× =
( ) ( )
( ) ( ) ( )3 30 0
3
' ' '
' '
4 ' 4 '
r r
J r J r r r
B r A r d r d r
r r r r
µ µ
π π
× −
= ∇ × = ∇ × = ÷ ÷− −
∫ ∫
Where we used ( ) ( )
0
' : 1/ 'r r rJ J r J r rφ φ φ φ∇ × = ∇ × + ∇ × = −
14243
Derivation of Biot-Savart Law from Ampère’s Law
Poison’s Equation
Solution for an unbounded volume
Ampère Law
Félix Savart
1791 - 1841
20. 20
SOLO
1831Electromagnetism
On 29th August 1831, using his "induction ring", Faraday made one
of his greatest discoveries - electromagnetic induction: the
"induction" or generation of electricity in a wire by means of the
electromagnetic effect of a current in another wire. The induction ring
was the first electric transformer. In a second series of experiments in
September he discovered magneto-electric induction: the production
of a steady electric current. To do this, Faraday attached two wires
through a sliding contact to a copper disc. By rotating the disc between
the poles of a horseshoe magnet he obtained a continuous direct
current. This was the first generator.
Michael Faraday
1791- 1867
Magnetic Field IntensityH
[ ]1−
⋅mA
Electric DisplacementD
[ ]2−
⋅⋅ msA
Electric Field IntensityE
[ ]1−
⋅mV
Magnetic InductionB
[ ]2−
⋅⋅ msV
→→
⋅
∂
∂
−=⋅ ∫∫∫ dS
t
B
dlE
SC
t
B
E
∂
∂
−=×∇
→
dl
→
dS
C
B
E
The voltage induced in a
coil moving through a
non-uniform magnetic
field was demonstrated
by this apparatus. As the
coil is removed from the
field of the bar magnets,
the coil circuit is broken
and a spark is observed
at the gap.
The first
transformer:
Two coils
wound on an
iron toroid.
http://www.ece.umd.edu/~taylor/frame1.htm
21. 21
MAXWELL’s EQUATIONS
1. AMPÈRE’s CIRCUIT LW (A) (1820)
SOLO
2. FARADAY’s INDUCTION LAW (F) (1831)
Electric DisplacementD
[ ]2−
⋅⋅ msA
Magnetic Field IntensityH
[ ]1−
⋅mA
Current DensityJ
[ ]2−
⋅mA
André-Marie Ampère
1775-1836
→→
⋅
∂
∂
−=⋅ ∫∫∫ dS
t
B
dlE
SC
t
B
E
∂
∂
−=×∇
→
dl
→
dS
C
B
E
Electric Field IntensityE
[ ]1−
⋅mV
Magnetic InductionB
[ ]2−
⋅⋅ msV
Michael Faraday
1791-1867
The following four equations describe the Electromagnetic Field and where
first given by Maxwell in 1864 (in a different notation) and are known as
MAXWELL’s EQUATIONS
22. 22
MAXWELL’s EQUATIONSSOLO
4. GAUSS’ LAW – MAGNETIC (GM)
dV
→
dS
V
0=⋅∫∫
→
S
dSB
B
0=⋅∇ B
Magnetic InductionB
[ ]2−
⋅⋅ msV
3. GAUSS’ LAW – ELECTRIC (GE)
dV
→
dS
V
∫∫∫∫∫ =⋅
→
VS
dVdSD ρ
D
ρ=⋅∇ D
ρ
Electric DisplacementD
[ ]2−
⋅⋅ msA
Free Charge Distributionρ [ ]3−
⋅⋅ msA
GAUSS’ ELECTRIC (GE) & MAGNETIC (GM) LAWS developed by Gauss
in 1835, but published in 1867.
Karl Friederich Gauss
1777-1855
Return to Table of Content
23. 23
James C. Maxwell
(1831-1879)
ELECTROMAGNETICSSOLO
Magnetic Field IntensityH
[ ]1−
⋅mA
Electric DisplacementD
[ ]2−
⋅⋅ msA
Electric Field IntensityE
[ ]1−
⋅mV
Magnetic InductionB
[ ]2−
⋅⋅ msV
Electric Current DensityeJ
[ ]2−
⋅mA
Free Electric Charge Distributioneρ [ ]3−
⋅⋅ msA
Fictious Magnetic Current DensitymJ
[ ]2−
⋅mV
Fictious Free Magnetic Charge Distributionmρ
[ ]3−
⋅⋅ msV
MAXWELL’S SYMMETRIC EQUATIONS FOR THE
ELECTROMAGNETIC FIELD
e
S
e
C
J
t
D
HSd
t
D
JdlH
+
∂
∂
=×∇⇒•
∂
∂
+=• ∫∫∫
→
)1( AMPÈRE’S LAW
t
B
JESd
t
B
JdlE m
S
m
C
∂
∂
−−=×∇⇒•
∂
∂
+−=• ∫∫∫
→
)2( FARADAY’S LAW
e
V
e
S
DdvSdD ρρ =•∇⇒=• ∫∫∫∫∫
)3( GAUSS’ ELECTRIC LAW
m
V
m
S
BdvSdB ρρ =•∇⇒=• ∫∫∫∫∫
)4( GAUSS’ MAGNETIC LAW
24. 24
ELECTROMAGNETICSSOLO
SYMMETRIC MAXWELL’s EQUATIONS
Magnetic Field IntensityH
[ ]1−
⋅mA
Electric DisplacementD
[ ]2−
⋅⋅ msA
Electric Field IntensityE
[ ]1−
⋅mV
Magnetic InductionB
[ ]2−
⋅⋅ msV
Electric Current DensityeJ
[ ]2−
⋅mA
Free Electric Charge Distributioneρ [ ]3−
⋅⋅ msA
Fictious Magnetic Current DensitymJ
[ ]2−
⋅mV
Fictious Free Magnetic Charge Distributionmρ
[ ]3−
⋅⋅ msV
1. AMPÈRE’S CIRCUIT LW (A) eJ
t
D
H
+
∂
∂
=×∇
2. FARADAY’S INDUCTION LAW (F)
mJ
t
B
E
−
∂
∂
−=×∇
3. GAUSS’ LAW – ELECTRIC (GE)
eD ρ=⋅∇
4. GAUSS’ LAW – MAGNETIC (GM) mB ρ=⋅∇
Although magnetic sources are not physical they are often introduced as electrical
equivalents to facilitate solutions of physical boundary-value problems.
André-Marie Ampère
1775-1836
Michael Faraday
1791-1867
Karl Friederich Gauss
1777-1855
25. 25
ELECTROMAGNETICSSOLO
SYMMETRIC MAXWELL’s EQUATIONS (continue – 1)
eJ
t
D
H
+
∂
∂
=×∇mJ
t
B
E
−
∂
∂
−=×∇
eD ρ=⋅∇
mB ρ=⋅∇
From the Symmetric Maxwell’s Equations we can see that we obtain the same equations
by performing the following operations.
DUALITY
⇓
⇓
−
⇓
⇓
−
⇓
⇓
−
⇓
⇓
⇓
−
⇓
µ
ε
ε
µ
ρ
ρ
ρ
ρ
e
m
m
e
e
m
m
e
J
J
J
J
E
H
H
E
B
D
D
B
The Maxwell’s Equations are symmetric and dual.
eJ
t
D
H
+
∂
∂
=×∇ mJ
t
B
E
−
∂
∂
−=×∇
mB ρ=⋅∇
eD ρ=⋅∇
26. 26
ELECTROMAGNETICSSOLO
SYMMETRIC MAXWELL’s EQUATIONS (continue – 2)
From the Symmetric Maxwell’s Equations
( ) 00 =
∂
∂
+⋅∇⇒⋅∇+⋅∇
∂
∂
=×∇⋅∇=⇒
=⋅∇
+
∂
∂
=×∇
t
JJD
t
H
D
J
t
D
H e
ee
e
e ρ
ρ
( ) 00 =
∂
∂
+⋅∇⇒⋅∇−⋅∇
∂
∂
−=×∇⋅∇=⇒
=⋅∇
−
∂
∂
−=×∇
t
JJB
t
E
B
J
t
B
E m
mm
m
m ρ
ρ
CONSERVATION OF ELECTRICAL AND MAGNETIC CHARGES
0=
∂
∂
+⋅∇
t
J e
e
ρ
0=
∂
∂
+⋅∇
t
J m
m
ρ
Therefore
Return to Table of Content
27. 27
ELECTROMAGNETICSSOLO
CONSTITUTIVE RELATIONS
Homogeneous Medium – Medium properties do not vary from point to point
and are the same for all points.ε µ
Isotropic Medium – Medium properties are the same in all directions
and are scalars.ε µ
Linear Medium – The effects of all different fields can be added linearly
(Superposition of different fields).
For Linear and Isotropic Medium we have:
ED
ε=
HB
µ=
where: 0εε eK=
0µµ mK=
- Dielectric Constant (or Relative Permitivity)eK
- Relative PermeabilitymK
The simpler case:
28. 28
ELECTROMAGNETICSSOLO
CONSTITUTIVE RELATIONS (continue - 1)
The most general form of Linear Constitutive Relations is:
Classification of Media
dyadicsxwhere
H
E
B
D
33,,, =
=
µζξε
µζ
ξε
Classification according to the functional dependence of the 6x6 matrix
µζ
ξε
1. Inhomogeneous: function of space coordinates
2. Nonstationary: function of time
3. Time-dispersive: function of time derivatives
4. Space-dispersive: function of space derivatives
5. Nonlinear: function of the electromagnetic field
29. 29
ELECTROMAGNETICSSOLO
CONSTITUTIVE RELATIONS (continue - 3)
Classification of Media (continue - 2)
In general 0,0,0,0
≠==≠ µζξε
Anisotropic Electromagnetic - medium described by both 0,0
≠≠ µε
Anisotropic Electric - medium described by 0
≠ε
Anisotropic Magnetic - medium described by 0
≠µ
If is symmetric, it can be diagonalized0
≠ε
=
z
y
x
ε
ε
ε
ε
00
00
00
Uniaxial zyx εεε ≠= (thetragonal, hexagonal,
rombohedral crystals)
Biaxial zyx εεε ≠≠ (orthohombic, monoclinic,
triclinic crystals)
Isotropic zyx εεε ==
This is called an Anisotropic Medium.
If or is Hermitian; i.e.0
≠ε 0
≠µ
( )
Transposeconjugate
conjugateTranspose
a
aj
ja
T
z
-T,-*
,-H
UUUU *H
==
−=
00
0
0
α
α
Is gyroelectric or gyromagnetic depending
on whether stands for or . If both
tensors are of this form the medium is
gyroelectromagnetic.
ε
µ
U
µζ
ξε
30. 30
ELECTROMAGNETICSSOLO
CONSTITUTIVE RELATIONS (continue - 4)
Classification of Media (continue - 3)
In general 0,0,0,0
≠≠≠≠ µζξε This is called an Bianisotropic Medium.
Such properties have been observed in antiferromagnatic chromium oxide
( antiferromagnetic materials are ones in which it is enerically favorable for
neighboring dipoles to take an antiparallel orientation; see Ramo, Whinery, and
Van Duzer (1965), pg. 145)
−−
−−
−=
**
**
4 µµζζ
ξξεεω
j
G
mediumlosslessundefinite
mediumpassivedefinitenegative
mediumactivedefinitepositive
⇒
⇒
⇒
G
G
G
In this case, we have the following classification (see development later)
Return to Table of Content
31. 31
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Boundary Conditions
( ) ( ) ldtHtHhldtHldtHldH
h
C
2211
0
2211
ˆˆˆˆ ⋅+⋅=Θ+⋅+⋅=⋅
→→
∫
where are unit vectors along C in region (1) and (2), respectively, and21
ˆ,ˆ tt
2121
ˆˆˆˆ −×=−= nbtt
- a unit vector normal to the boundary between region (1) and (2)21
ˆ −n
- a unit vector on the boundary and normal to the plane of curve Cbˆ
Using we obtainbaccba
⋅×≡×⋅
( ) ( ) ( )[ ] ldbkldbHHnldnbHHldtHH e
ˆˆˆˆˆˆ 21212121121 ⋅=⋅−×=×⋅−=⋅− −−
Since this must be true for any vector that lies on the boundary between
regions (1) and (2) we must have:
bˆ
( ) ekHHn
=−×− 2121
ˆ
∫∫∫ ⋅
∂
∂
+=⋅
→
S
e
C
Sd
t
D
JdlH
( ) dlbkbdlh
t
D
JSd
t
D
J e
h
e
S
e
ˆˆ
0
⋅=⋅
∂
∂
+=⋅
∂
∂
+
→
∫∫
AMPÈRE’S LAW
[ ]1
0
lim: −
→
⋅
∂
∂
+= mAh
t
D
Jk e
h
e
32. 32
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Boundary Conditions (continue – 1)
( ) ( ) ldtEtEhldtEldtEldE
h
C
2211
0
2211
ˆˆˆˆ ⋅+⋅=Θ+⋅+⋅=⋅
→→
∫
where are unit vectors along C in region (1) and (2), respectively, and21
ˆ,ˆ tt
2121
ˆˆˆˆ −×=−= nbtt
- a unit vector normal to the boundary between region (1) and (2)21
ˆ −n
- a unit vector on the boundary and normal to the plane of curve Cbˆ
Using we obtainbaccba
⋅×≡×⋅
( ) ( ) ( )[ ] ldbkldbEEnldnbEEldtEE m
ˆˆˆˆˆˆ 21212121121 ⋅−=⋅−×=×⋅−=⋅− −−
Since this must be true for any vector that lies on the boundary between
regions (1) and (2) we must have:
bˆ
( ) mkEEn
−=−×− 2121
ˆ
∫∫∫ ⋅
∂
∂
+−=⋅
→
S
m
C
Sd
t
B
JdlE
( ) dlbkbdlh
t
B
JSd
t
B
J m
h
m
S
m
ˆˆ
0
⋅=⋅
∂
∂
+=⋅
∂
∂
+
→
∫∫
FARADAY’S LAW
[ ]1
0
lim: −
→
⋅
∂
∂
+= mVh
t
B
Jk m
h
m
33. 33
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Boundary Conditions (continue – 2)
( ) ( ) SdnDnDhSdnDSdnDSdD
h
S
2211
0
2211
ˆˆˆˆ ⋅+⋅=Θ+⋅+⋅=⋅
→
∫∫
where are unit vectors normal to boundary pointing in region (1) and (2),
respectively, and
21
ˆ,ˆ nn
2121
ˆˆˆ −=−= nnn
- a unit vector normal to the boundary between region (1) and (2)21
ˆ −n
( ) ( ) SdSdnDDSdnDD eσ=⋅−=⋅− −2121121
ˆˆ
Since this must be true for any dS on the boundary between regions (1) and (2)
we must have:
( ) eDDn σ=−⋅− 2121
ˆ
( ) dSdShdv e
h
e
V
e σρρ
0→
==∫∫∫
GAUSS’ LAW - ELECTRIC
[ ]1
0
lim: −
→
⋅⋅= msAhe
h
e ρσ
∫∫∫∫∫ =•
V
e
S
dvSdD ρ
34. 34
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Boundary Conditions (continue – 3)
( ) ( ) SdnBnBhSdnBSdnBSdB
h
S
2211
0
2211
ˆˆˆˆ ⋅+⋅=Θ+⋅+⋅=⋅
→
∫∫
where are unit vectors normal to boundary pointing in region (1) and (2),
respectively, and
21
ˆ,ˆ nn
2121
ˆˆˆ −=−= nnn
- a unit vector normal to the boundary between region (1) and (2)21
ˆ −n
( ) ( ) SdSdnBBSdnBB mσ=⋅−=⋅− −2121121
ˆˆ
Since this must be true for any dS on the boundary between regions (1) and (2)
we must have:
( ) mBBn σ=−⋅− 2121
ˆ
( ) dSdShdv m
h
m
V
m σρρ
0→
==∫∫∫
GAUSS’ LAW – MAGNETIC
[ ]1
0
lim: −
→
⋅⋅= msVhm
h
m ρσ
∫∫∫∫∫ =•
V
m
S
dvSdB ρ
35. 35
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Boundary Conditions (summary)
( ) mkEEn
−=−×− 2121
ˆ FARADAY’S LAW
( ) ekHHn
=−×− 2121
ˆ AMPÈRE’S LAW [ ]1
0
lim: −
→
⋅
∂
∂
+= mAh
t
D
Jk e
h
e
[ ]1
0
lim: −
→
⋅
∂
∂
+= mVh
t
B
Jk m
h
m
( ) eDDn σ=−⋅− 2121
ˆ
GAUSS’ LAW
ELECTRIC
[ ]1
0
lim: −
→
⋅⋅= msAhe
h
e ρσ
( ) mBBn σ=−⋅− 2121
ˆ
GAUSS’ LAW
MAGNETIC
[ ]1
0
lim: −
→
⋅⋅= msVhm
h
m ρσ
36. 36
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Boundary Conditions for Perfect Electric Conductor (PEC)
( ) 0ˆ 2121
=−×− EEn FARADAY’S LAW
( ) ekHHn
=−×− 2121
ˆ AMPÈRE’S LAW
( ) eDDn σ=−⋅− 2121
ˆ
GAUSS’ LAW
ELECTRIC
( ) 0ˆ 2121 =−⋅− BBn
GAUSS’ LAW
MAGNETIC
ekHn
=×− 121
ˆ
0ˆ 121
=×− En
eDn σ=⋅− 121
ˆ
0ˆ 121 =⋅− Bn
02
=H
02
=B
02
=E
02
=D
37. 37
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Boundary Conditions for Perfect Magnetic Conductor (PMC)
( ) mkEEn
−=−×− 2121
ˆ FARADAY’S LAW
( ) 0ˆ 2121
=−×− HHn AMPÈRE’S LAW
( ) 0ˆ 2121 =−⋅− DDn
GAUSS’ LAW
ELECTRIC
( ) mBBn σ=−⋅− 2121
ˆ
GAUSS’ LAW
MAGNETIC
0ˆ 121
=×− Hn
mkEn
−=×− 121
ˆ
0ˆ 121 =⋅− Dn
mBn σ=⋅− 121
ˆ
02
=H
02
=B
02
=E
02
=D
Return to Table of Content
38. 38
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Energy and Momentum
Let start from Ampère and Faraday Laws
∂
∂
−=×∇⋅
+
∂
∂
=×∇⋅−
t
B
EH
J
t
D
HE e
EJ
t
D
E
t
B
HHEEH e
⋅−
∂
∂
⋅−
∂
∂
⋅−=×∇⋅−×∇⋅
( )HEHEEH
×⋅∇=×∇⋅−×∇⋅But
Therefore we obtain
( ) EJ
t
D
E
t
B
HHE e
⋅−
∂
∂
⋅−
∂
∂
⋅−=×⋅∇
First way
This theorem was discovered by Poynting in 1884 and later in the same year by Heaviside.
39. 39
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Energy and Momentum (continue -1)
We identify the following quantities
-Power density of the current densityEJe
⋅
( )HEDE
t
BH
t
EJe
×⋅∇−
⋅
∂
∂
−
⋅
∂
∂
−=⋅
2
1
2
1
⋅
∂
∂
=⋅= BH
t
pBHw mm
2
1
,
2
1
⋅
∂
∂
=⋅= DE
t
pDEw ee
2
1
,
2
1
( )HEpR
×⋅∇=
eJ
-Magnetic energy and power densities, respectively
-Electric energy and power densities, respectively
-Radiation power density
For linear, isotropic electro-magnetic materials we can write( )HBED
00 , µε ==
( )DE
tt
D
E
ED
⋅
∂
∂
=
∂
∂
⋅
=
2
10ε
( )BH
tt
B
H
HB
⋅
∂
∂
=
∂
∂
⋅
=
2
10µ
40. 40
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Energy and Momentum (continue – 3)
Let start from the Lorentz Force Equation (1892) on the free charge
( )BvEF e
×+= ρ
Free Electric Chargeeρ [ ]3−
⋅⋅ msA
Velocity of the chargev
[ ]1−
⋅sm
Electric Field IntensityE
[ ]1−
⋅mV
Magnetic InductionB
[ ]2−
⋅⋅ msV
Hendrik Antoon Lorentz
1853-1928
eρ
Force on the free chargeF
[ ]Neρ
Second way
41. 41
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Energy and Momentum (continue – 4)
The power density of the Lorentz Force the charge
( )
( )
EJBvEvp e
Bvv
Jv
e
ee
⋅=×+⋅=
=×⋅
=
0
ρ
ρ
or
( ) ( ) ( )
( ) ( )[ ]
( )HE
t
B
HE
t
D
E
t
D
HEEH
E
t
D
HEJp
t
B
E
HEHEEH
J
t
D
H
e
e
×⋅∇−
∂
∂
⋅+⋅
∂
∂
−=
⋅
∂
∂
−×⋅∇−×∇⋅=
⋅
∂
∂
−×∇=⋅=
∂
∂
−=∇×
×⋅∇=∇×⋅−∇×⋅
+
∂
∂
=∇×
eρ
42. 42
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Energy and Momentum (continue – 5)
( )HEDE
t
BH
t
EJe
×⋅∇−
⋅
∂
∂
−
⋅
∂
∂
−=⋅
2
1
2
1
Let integrate this equation over a constant volume V
∫∫∫∫∫∫∫∫∫∫∫∫ ×∇−
⋅−
⋅−=⋅
VVVV
e dvSdvDE
td
d
dvBH
td
d
dvEJ
2
1
2
1
If we have sources in V then instead of
we must use
E
source
EE
+
Use Ohm Law (1826)
( )source
ee EEJ
+= γ
=
∂
∂
∫∫∫∫∫∫ VV
td
d
t
Georg Simon Ohm
1789-1854
source
e
e
EJE
−=
γ
1
For linear, isotropic electro-magnetic materials ( )HBED
00 , µε ==
43. 43
SOLO ELECTROMAGNETICS BOUNDARY CONDITIONS
Energy and Momentum (continue – 6)
∫∫∫∫∫∫∫∫∫∫∫∫∫ ⋅∇+
⋅+
⋅+=⋅
VVVR
n
V
source
e dvSdvDE
td
d
dvBH
td
d
dRIdvEJ
2
1
2
12
∫∫∫
⋅=
V
FieldMagnetic dvBH
td
d
P
2
1
∫∫∫
⋅=
V
FieldElectric dvDE
td
d
P
2
1
∫∫∫∫∫ ⋅=⋅∇=
SV
Radiation SdSdvSP
∫∫∫ ⋅=
V
source
eSource dvEJP
( ) ( )
∫∫∫∫
∫∫∫∫∫∫∫∫∫∫∫∫∫∫∫
⋅−=
⋅−⋅=⋅−⋅⋅=⋅
V
source
e
R
n
V
source
e
L S e
ee
V
source
e
L S e
ee
V
e
dvEJdRI
dvEJ
dS
dl
dSJdSJdvEJldSdJJdvEJ
2
11
γγ
∫=
R
nJoule dRIP
2
RadiationFieldMagneticFieldElectricJouleSource PPPPP +++=
For linear, isotropic electro-magnetic materials( )HBED
00 , µε ==
R – Electric Resistance
Define the Umov-Poynting vector: [ ]2
/ mwattHES
×=
The Umov-Poynting vector was discovered by Umov in 1873, and rediscovered by
Poynting in 1884 and later in the same year by Heaviside.
44. 44
ELECTROMAGNETICSSOLO
EM People
John Henry Poynting
1852-1914
Oliver Heaviside
1850-1925
Nikolay Umov
1846-1915
1873
“Theory of interaction on final
distances and its exhibit to
conclusion of electrostatic and
electrodynamic laws”
1884 1884
Umov-Poynting vector
HES
×=
Return to Table of Content
45. 45
ELECTROMAGNETICSSOLO
Monochromatic Planar Wave Equations
Let assume that can be written as:( ) ( )trHtrE ,,,
( ) ( ) ( ) ( ) ( ) ( )tjrHtrHtjrEtrE 00 exp,,exp, ωω
==
where are phasor (complex)
vectors.
( ) ( ){ } ( ){ } ( ) ( ){ } ( ){ }rHjrHrHrEjrErE
ImRe,ImRe +=+=
We have ( ) ( ) ( ) ( ) ( )tjrEjtj
t
rEtrE
t
00 expexp, ωωω
=
∂
∂
=
∂
∂
Hence
( )
( )
( )
=⋅∇
=⋅∇
−−=×∇
+=×∇
⇒
=⋅∇
=⋅∇
−
∂
∂
−=×∇
+
∂
∂
=×∇
=
∂
∂
m
e
m
e
j
t
m
e
m
e
B
D
JBjE
JDjH
BGM
DGE
J
t
B
EF
J
t
D
HA
ρ
ρ
ω
ω
ρ
ρ
ω
)(
47. 47
ELECTROMAGNETICSSOLO
Fourier Transform
The Fourier transform of can be written as:( ) ( )trHtrE ,,,
( ) ( ) ( ) ( ) ( ) ( )
( ) ( ) ( ) ( ) ( ) ( )∫∫
∫∫
∞
∞−
∞
∞−
∞
∞−
∞
∞−
−==
−==
dttjtrHrHdtjrHtrH
dttjtrErEdtjrEtrE
ωωωωω
π
ωωωωω
π
exp,,&exp,
2
1
,
exp,,&exp,
2
1
,
( ) ( )
( ) ( ) ∞<=
∞<=
∫∫
∫∫
∞
∞−
∞
∞−
∞
∞−
∞
∞−
ωω
π
ωω
π
drHdttrH
drEdttrE
22
22
,
2
1
,
,
2
1
,
JEAN FOURIER
1768-1830
A Sufficient Condition for the Existence of the Fourier
Transform is:
48. 48
ELECTROMAGNETICSSOLO
( )
( )
×∇−×∇−=×∇×∇
×∇+×∇=×∇×∇
−−=×∇
+=×∇
⇒
−−=×∇×∇
+=×∇×∇ =
=
m
e
m
e
ED
HB
m
e
JHjE
JEjH
JHjE
JEjH
JBjE
JDjH
ωµ
ωε
ωµ
ωε
ω
ω ε
µ
( ) me JJjEkE
×∇−−=−×∇×∇ ωµ2
( ) em JJjHkH
×∇+−=−×∇×∇ ωε2 λ
ππ
µεω
λ
22 f
c
c
f
k
=
∆
===
Using the vector identity ( ) ( ) ( ) AAA
∇⋅∇−⋅∇∇=×∇×∇
For a Homogeneous, Linear and Isotropic Media:
=⋅∇
=⋅∇
⇒
=⋅∇
=⋅∇ =
=
µ
ρ
ε
ρ
ρ
ρ ε
µ
m
e
ED
HB
m
e
H
E
B
D
ε
ρ
ωµ e
me JJjEkE
∇
+×∇+=+∇
22
µ
ρ
ωε m
em JJjHkH
∇
+×∇−=+∇
22
and
we obtain
Monochromatic Planar Wave Equations (continue - 1)
49. 49
ELECTROMAGNETICSSOLO
Assume no sources:
we have
Monochromatic Planar Wave Equations (continue - 2)
0,0,0,0 ==== meme JJ ρρ
022
=+∇ EkE
022
=+∇ HkH
nkk
n
k
0
00
00
0
=
==
∆
εµ
µε
εµωµεω
( ) ( ) ( )
( ) ( ) ( )
==
==
⋅−
⋅−
rktjtj
rktjtj
eHerHtrH
eEerEtrE
ωω
ωω
ω
ω
0
0
,,
,,
( ) 022
=+∇⇒
⋅−=∇⋅∇⇒−=∇
⋅−
⋅−⋅−⋅−⋅−
rkj
rkjrkjrkjrkj
ek
ekkeekje
Helmholtz Wave Equations
satisfy the Helmholtz wave equations( ) ( )ωω ,,, rHrE
( )
( )
=
=
⋅−
⋅−
rkj
rkj
eHrH
eErE
0
0
,
,
ω
ω
Assume a progressive wave of phase ( )rkt
⋅−ω (a regressive wave has the phase) ( )rkt
⋅+ω
For a Homogeneous, Linear and Isotropic Media
k
0E
0H
r
t
k
Planes for which
constrkt =⋅−
ω
50. 50
ELECTROMAGNETICSSOLO
To satisfy the Maxwell equations for a source free media we must have:
Monochromatic Planar Wave Equations (continue - 3)
we haveUsing: 1ˆˆ&ˆˆ =⋅== sss
c
n
sk ωεµω
=⋅∇
=⋅∇
−=×∇
=×∇
0
0
H
E
HjE
EjH
ωµ
ωε
=⋅
=⋅
=×
−=×
0ˆ
0ˆ
ˆ
ˆ
0
0
00
00
Hs
Es
HEs
EHs
ε
µ
µ
ε
sˆ
Planar Wave
0E
0H
r
=⋅−
=⋅−
−=×−
=×−
⇒
⋅−
⋅−
⋅−⋅−
⋅−⋅−
−=∇ ⋅−⋅−
0
0
0
0
00
00
rkj
rkj
rkjrkj
rkjrkj
ekje
eHkj
eEkj
eHjeEkj
eEjeHkj
rkjrkj
ωµ
ωε
=⋅
=⋅
=×
−=×
0
0
0
0
00
00
Hk
Ek
HEk
EHk
µω
εω
For a Homogeneous, Linear and Isotropic Media:
Return to Table of Content
51. 51
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
0
0
0
0
m
e
m
e
B
D
J
t
B
E
J
t
D
H
ρ
ρ
=⋅∇
=⋅∇
−
∂
∂
−=×∇
+
∂
∂
=×∇
( ) ( ) ( )
∫
+∞
∞−
⋅−
= dkekEtrE rktj
ω
0,
ωω
ωω
j
t
eje
t
rs
c
n
tjrs
c
n
tj
→
∂
∂
⇒=
∂
∂
⋅−
⋅−
ˆˆ
kjs
c
n
jes
c
n
je
rs
c
n
tjrs
c
n
tj
−=−→∇⇒−=∇
⋅−
⋅−
ˆˆ
ˆˆ
ωω
ωω
0ˆ
0ˆ
ˆ
ˆ
=⋅
=⋅
=×
−=×
Bs
Ds
BEs
c
n
DHs
c
n
( )
( )DEBH
tt
D
E
t
B
H
HEEHHES
HB
ED
⋅+⋅
∂
∂
−=
∂
∂
⋅−
∂
∂
⋅−=
×∇⋅−×∇⋅=×⋅∇=⋅∇
⋅=
⋅= 2
1µ
ε
( ) emUDEBHS
k
Ss
c
n
=⋅+⋅=⋅=⋅
2
1
ˆ
ω
Maxwell’s
Symmetric Equations
Planar Wave
0
0
=⋅
=⋅
=×
−=×
Bk
Dk
BEk
DHk
ω
ω
ωj
t
→
∂
∂
s
c
n
j ˆω−→∇
ωj
t
→
∂
∂
kj
−→∇
vector phasor
vector phasor
s
c
n
k ˆω=
52. 52
SOLO ELECTROMAGNETICS
Planar Wave Group Velocity
Consider a Planar Wave composed of
frequencies centered around ω0.
( ) ( ) ( )( )
∫
+∞
∞−
⋅−
= dkekEtrE rktkj
ω
0,
( ) ( ) +−
+= 0
0
0
kk
kd
d
k
ω
ωω
Expand ω(k), using Taylor series
around k0
( ) ( ) ( )
( )
∫
∞+
∞−
−
−
⋅−
−
⋅−
= dkekEetrE
kk
kk
rkk
t
kd
d
j
rktj
0
0
0
0
00
0,
ω
ω
The Phase of the Group of Waves is ( )
0
0
0
0
kk
kk
rkk
t
kd
d
g
−
−
⋅−
−
=
ω
ϕ
To find the velocity of phase of the group of
waves consider the points for which φg = const
( ) 0
0
0
0
=
−
⋅−
−
⇒
kk
rdkk
td
kd
d
g
d
ω
ϕ
The Group Velocity of the Planar Wave is
( )
0
0
0 kk
kk
kd
d
krd
g td
rd
v
−
−
=
=
=
ω
δ
Return to Table of Content
53. 53
SOLO ELECTROMAGNETICS
Phase Velocity, Energy (Ray) Velocity for Planar Waves
The phase of the field is given by
⋅−=⋅−= rs
c
n
trkt
ˆωωφ
For a constant phase front we have
⋅−=⋅−=⋅−== rds
c
n
dtrdskdtrdkdtd
ˆˆ0 ωωωφ
s
n
c
s
kdt
rd
v
srr
const
p
ˆˆ:
ˆ
===
=
=
ω
φ
Phase Velocity B
D
pv
E
H
HES
×=α
α
k
ev
PlanarWaves
n
c
ktd
rd
s ==⋅
ω
ˆ
n
c
S
S
vs e =⋅ :ˆ
( ) α
α
cosˆ
ˆ
cos
p
S
Ss
e
v
Ss
S
n
c
v
⋅
=
=
⋅
=
Define the phase velocity as
Define the energy flow velocity in the Poynting vector direction as
S
S
vSv ee =
→
1
( ) emUDEBHS
k
Ss
c
n
=⋅+⋅=⋅=⋅
2
1
ˆ
ω
( ) em
ee
U
S
S
Ssn
c
S
S
vv =
⋅
==
ˆ
1
:
Energy (Ray) Velocity
The electro-magnetic energy propagates along the Poynting vector .
For anisotropic media the Poynting vector is not collinear with .k
HES ×=
Return to Table of Content
Electromagnetic Energy Density
54. 54
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
A wave packet can be viewed as a superposition of monochromatic waves, with different
frequencies ω and wave vector that must satisfy the Maxwell’s equationsk
EHk
HEk
⋅−=×
⋅=×
εω
µω
Suppose that the wave vector changes by an infinitesimal amount , that determines
changes
k
k
δ
HE δδωδ ,,
HHHEkEk ⋅⋅+⋅=×+× δµωµωδδδ
( )EEEHkHk −⋅⋅−⋅−=×+× δεωεωδδδ
( ) ( ) ( ) ( )
( ) ( ) ( ) ( )EEEEEHkHEk
HHHHHEkHEk
δεωεωδδδ
δµωµωδδδ
⋅⋅+⋅⋅=×⋅−×⋅
⋅⋅+⋅⋅=×⋅+×⋅
( ) ( )
( ) ( ) 0
2
00
=⋅+×⋅+⋅−×⋅−=
⋅⋅+⋅⋅−×⋅
EHkEHEkH
HHEEHEk
εωδµωδ
µεωδδ
( ) ( ) ( )BACACBCBA
×⋅≡×⋅≡×⋅
55. 55
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
( )
( )
e
em
vk
U
S
k
HHEE
HEk
⋅=⋅=
⋅⋅+⋅⋅
×⋅
= δδ
µε
δ
ωδ
2
1
( ) gk vkk
⋅=∇⋅= δωδωδ
- Energy (Ray) Velocityev
From the definition of Group Velocity: gv
since those relations are true for all: k
δ eg vv
=
For a monochromatic wave δω=0, therefore
( ) 0=×⋅=⋅ HEkSk
δδ
( ) ( ) 02 =⋅⋅+⋅⋅−×⋅ HHEEHEk µεωδδ
56. 56
ELECTROMAGNETICSSOLO
Consider an Electric Anisotropic Media
General Symmetric
=⋅∇
=⋅∇
−=×∇
⋅=×∇
0
0
B
D
HjE
EjH
µω
εω
For a Homogeneous, Linear and Anisotropic Media:
=
333231
232221
131211
εεε
εεε
εεε
ε
=
z
y
x
D
ε
ε
ε
ε
00
00
00
Diagonalized
Principal Axis
TTD
εε 1−
=
−−=×∇×∇
+⋅=×∇×∇
m
e
JHjE
JEjH
µω
εω
( )
( )
×∇−×∇−=×∇×∇
×∇+⋅×∇=×∇×∇
m
e
JHjE
JEjH
ωµ
εω
( ) me JJjEE ×∇−×∇−=×∇×∇ µω
ε
ε
µεω
0
0
2
Planar Waves in an Source-less Anisotropic Electric Media
Return to Table of Content
57. 57
ELECTROMAGNETICSSOLO
According to the principle of superposition these two fields can exist separately or be
superimposed without disturbing each other.
( )1221 HEHE
×−×⋅∇
Consider two distinct fields and. 11, HE
22 , HE
Assumptions:
1.The two fields are harmonic functions of time and of the same frequency.
2.The medium is linear.
3.The point considered is not inside a source and Ohm Law applies.
∂
∂
+⋅+
∂
∂
⋅+
∂
∂
+⋅−
∂
∂
⋅=
t
D
JE
t
B
H
t
D
JE
t
B
H ee
1
12
2
1
2
21
1
2
12212112 HEEHHEEH
×∇⋅+×∇⋅−×∇⋅−×∇⋅=
( ) ( )1122122112 DjJEBHjDjJEBHj ee
j
t
ωωωω
ω
+⋅+⋅++⋅−⋅−=
=
∂
∂
( ) ( ) 0
0
1122122112
21 ==⋅=
⋅=
=⋅+⋅+⋅⋅+⋅+⋅−⋅⋅−=
ee JJ
ee
ED
HB
EjJEHHjEjJEHHj εωµωεωµω
ε
µ
Lorentz’s Lemma
58. 58
ELECTROMAGNETICSSOLO
Lorentz’s Lemma (continue)
( ) ( )1221 HEHE
×⋅∇=×⋅∇
For the two distinct fields and. 11, HE
22 , HE
Hendrik Antoon Lorentz
1853-1928
For a Monochromatic Planar Wave
( ) ( ) ( )
( ) ( ) ( )
==
==
⋅−
⋅−
rktjtj
rktjtj
eHerHtrH
eEerEtrE
ωω
ωω
ω
ω
0
0
,,
,,
( ) ( ) ( )rktjrktjrktj
eskjekje
⋅−⋅−⋅−
−=−=∇ ωωω
ˆ
Lorentz’s Lemma can be written
( ) ( )1221 HEkHEk
×⋅=×⋅
59. 59
ELECTROMAGNETICSSOLO
Lorentz’s Reciprocity Theorem
( )
( )222
111
se
se
EEJ
EEJ
+=
+=
σ
σ
This is the more general case that does not exclude the sources.
( ) 12211221 ee JEJEHEHE
⋅−⋅=×−×⋅∇Ohm’s Law:
are the applied electric field intensities within the sources21, ss EE
( )1221 HEHE
×−×⋅∇
∂
∂
+⋅+
∂
∂
⋅+
∂
∂
+⋅−
∂
∂
⋅=
t
D
JE
t
B
H
t
D
JE
t
B
H ee
1
12
2
1
2
21
1
2
12212112 HEEHHEEH
×∇⋅+×∇⋅−×∇⋅−×∇⋅=
( ) ( )1122122112 DjJEBHjDjJEBHj ee
j
t
ωωωω
ω
+⋅+⋅++⋅−⋅−=
=
∂
∂
( ) ( )
122112211212
21122211122112
esesssssss
ssssee
JEJEEEEEEEEE
EEEEEEEEEEJEJE
⋅−⋅=⋅−⋅−⋅+⋅=
⋅−⋅=+⋅−+⋅=⋅−⋅=
σσσσ
σσσσ
( ) ( )1122122112 EjJEHHjEjJEHHj ee
ED
HB
⋅+⋅+⋅⋅+⋅+⋅−⋅⋅−=
⋅=
⋅=
εωµωεωµω
ε
µ
60. 60
ELECTROMAGNETICSSOLO
Lorentz’s Reciprocity Theorem (continue - 1)
Integrate over a very large volume:
( ) 12211221 ee JEJEHEHE
⋅−⋅=×−×⋅∇
( ) ( )∫∫ ×−×⋅∇=⋅−⋅
VV
eses dvHEHEdvJEJE 12211221
( ) 11
22
21
21
0
0
0
0
1221 0
VoutsideE
VoutsideE
EE
HH
S
s
s
S
S
sdHEHE
=
=
==
==
⇐=⋅×−×=
→∞
→∞
∫
We obtained
( ) ( )∫∫ ⋅=⋅
V
es
V
es dvJEdvJE 1221
( ) 212121 bs
V
es
V
es IVdsJdlEdvJE =⋅=⋅ ∫∫
( ) 121212 bs
V
es
V
es IVdsJdlEdvJE =⋅=⋅ ∫∫
61. 61
ELECTROMAGNETICSSOLO
Lorentz’s Reciprocity Theorem (continue - 2)
The Reciprocity Theorem
1221 bsbs IVIV =
The current induced in 2 when 1 is energized, divided by the
voltage applied on 1, is the same as the current induced in 1
when 2 is energized, divided by the applied voltage on 2, as
long as the frequency and the impedances remain unchanged.
1221 bbss IIVV =⇔=
Return to Table of Content
62. 62
SOLO
( ) ( ) ( ) ( )
( ) ( )[ ]{ }
( ) ( ) ( ) ( )[ ] ( ) ( ) ( ) ( )[ ]
( ) ( ) ( ) ( ) ( ) ( )[ ]∫
∫
∫
∫∫
−+⋅+=
−+⋅−+=
=
⋅=⋅=
=
T
T
T
TEDT
e
dttjrErErEtjrE
T
dttjrEtjrEtjrEtjrE
T
dttjrEal
T
dttrEtrE
T
dttrDtrE
T
w
0
2**2
0
**
0
2
00
2exp,,,22exp,
4
1
exp,exp,exp,exp,
4
1
exp,Re
1
,,
1
,,
1
ωωωωωω
ε
ωωωωωωωω
ε
ωωε
ε
ε
But
( ) ( )[ ] ( )
( ) ( )[ ] ( ) 0
2
2exp
2exp
2
1
2exp
1
0
2
2exp
2exp
2
1
2exp
1
0
0
0
0
∞→
∞→
→
−
=−=−
→==
∫
∫
T
T
T
T
T
T
Tj
Tj
tj
Tj
dttj
T
Tj
Tj
tj
Tj
dttj
T
ω
ω
ω
ω
ω
ω
ω
ω
ω
ω
Therefore
( ) ( ) *
00
*
00
0
*
22
1
,,
2
EEeEeEdt
T
rErEw rkjrkj
T
e
εε
ωω
ε
=== ⋅−⋅
∫
Let compute the time averages of the electric and magnetic energy densities
ELECTROMAGNETICS
Energy Flux and Poynting Vector
For a Homogeneous, Linear and Isotropic Media
63. 63
SOLO
In the same way
( ) ( ) ( ) ( ) *
00
00
2
,,
1
,,
1
HHdttrHtrH
T
dttrBtrH
T
w
TT
m
µ
µ === ∫∫
Using the relations
( ) 00
ˆ HsEA ×−=
ε
µ
( ) 00
ˆ EsHF ×=
µ
ε
since and are real values , where * is the
complex conjugate, we obtain
S∇ )**,( SS ∇=∇=
( ) ( )
( ) ( )
( ) ( )[ ] ( ) e
m
e
wHkEHkEHkE
EkHEkHHHw
HkEHkEEEw
=×⋅=×⋅=×⋅=
×⋅=×⋅=⋅=
×⋅=×⋅=⋅=
*
00
*
0
*
00
**
0
*
00
*
00
*
00
*
00
*
00
*
00
ˆ
2
ˆ
2
ˆ
2
ˆ
2
ˆ
22
ˆ
2
ˆ
22
µεµεµε
µε
µ
εµµ
µε
ε
µεε
ELECTROMAGNETICS
( ) ( ) *
00
*
00
0
*
22
1
,,
2
EEeEeEdt
T
rErEw rkjrkj
T
e
εε
ωω
ε
=== ⋅−⋅
∫
Energy Flux and Poynting Vector (continue – 1)
For a Homogeneous, Linear and Isotropic Media:
Time-averaged Electric Energy Density
Time-averaged Magnetic Energy Density
64. 64
SOLO
Therefore
( ) ( )( )*
00
ˆ
2
rHkrEww me
×⋅==
µε
Within the accuracy of Geometrical Optics, the Time-averaged Electric and
Magnetic Energy Densities are equal.
( ) ( ) ( ) ( ) ( ) ( )( )*
0000
*
00
ˆ
22
rHkrErHrHrErEwww me
×⋅=⋅+⋅=+=
∗
µε
µε
The total energy will be:
The Poynting vector is defined as: ( ) ( ) ( )trHtrEtrS ,,:,
×=
( ) ( ) ( ) ( ) ( ) ( )[ ]
( ) ( )[ ] ( ) ( )[ ]∫
∫∫
−−
+×+=
×=×=×=
T
tjtjtjtj
T
tjtj
T
dterHerHerEerE
T
dterHerEal
T
dttrHtrE
T
trHtrES
0
**
00
,,
2
1
,,
2
11
,,Re
1
,,
1
,,
ωωωω
ωω
ϖϖϖϖ
ϖϖ
( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )[ ]
( ) ( ) ( ) ( )[ ]ωωωω
ωωωωωωωω ωω
,,,,
4
1
,,,,,,,,
4
11
**
0
2****2
rHrErHrE
dterHrErHrErHrEerHrE
T
T
tjtj
×+×=
∫ ×+×+×+×= −
[ ]
[ ]0
*
0
*
00
0
*
0
*
00
4
1
4
1
HEHE
eHeEeHeE rkjrkjrkjrkj
×+×=
×+×= ⋅−⋅⋅⋅−
The time average of the Poynting vector is:
John Henry Poynting
1852-1914
ELECTROMAGNETICS
Energy Flux and Poynting Vector (continue – 2)
For a Homogeneous, Linear and Isotropic Media:
Return to Table of Content
65. 65
SOLO
Assume the linear general constitutive relations
ELECTROMAGNETICS
( )
( )
( )
=⋅∇
=⋅∇
−−=×∇
+=×∇
m
e
m
e
BGM
DGE
JBjEF
JDjHA
ρ
ρ
ω
ω
)(
dyadicsxwhere
H
E
B
D
33,,, =
=
µζξε
µζ
ξε
( ) ( )
( ) ( )
−⋅+⋅−=×∇
+⋅+⋅=×∇
m
e
JHEjEF
JHEjHA
µζω
ξεω
Energy Flux and Poynting Vector for a Bianisotropic Medium
66. 66
SOLO ELECTROMAGNETICS
Let compute the following
( )
( )[ ] ( )[ ]
( ) me
HH
me
HH
JHJEHHEHHEEEj
JHEjHEJHEj
EHHEHE
⋅−⋅−⋅⋅−⋅⋅−⋅⋅+⋅⋅=
−⋅+⋅−⋅+⋅+⋅+⋅−−=
×∇⋅+×∇⋅−=×⋅∇
******
****
***
µζξεω
µζωξεω
( )
( )[ ] ( ) ( )[ ]
( ) ******
****
***
me
HH
m
HH
e
JHJEHHHEHEEEj
HJHEjJHEjE
EHHEHE
⋅−⋅−⋅⋅−⋅⋅−⋅⋅+⋅⋅−=
⋅−⋅+⋅−−++⋅+⋅⋅−=
×∇⋅+×∇⋅−=×⋅∇
µζξεω
µζωξεω
( ) ( )
( )
( ) ******
******
**
me
HH
me
HH
JHJEHHHEHEEEj
JHJEHHEHEHEEj
HEHE
⋅−⋅−⋅⋅−⋅⋅−⋅⋅+⋅⋅−
⋅−⋅−⋅⋅−⋅⋅−⋅⋅+⋅⋅=
×⋅∇+×⋅∇
µζξεω
µζξεω
( ) ( )
( ) ( )
−⋅+⋅−=×∇
+⋅+⋅=×∇
m
e
JHEjEF
JHEjHA
µζω
ξεω
Energy Flux and Poynting Vector for a Bianisotropic Medium (continue – 1)
67. 67
SOLO ELECTROMAGNETICS
( ) ( )
( )
( )
( ) ( ) ( ) ( )[ ]
( ) ( )
[ ] ( ) ( )mmeeHH
HH
mmee
HHHH
me
HH
me
HH
JHJHJEJE
H
E
jHE
JHJHJEJE
HHEHHEEEj
JHJEHHHEHEEEj
JHJEHHEHEHEEj
HEHE
⋅+⋅−⋅+⋅−
⋅
−−
−−
−⋅=
⋅+⋅−⋅+⋅+
⋅−⋅+⋅−⋅+⋅−⋅+⋅−⋅−=
⋅−⋅−⋅⋅−⋅⋅−⋅⋅+⋅⋅−
⋅−⋅−⋅⋅−⋅⋅−⋅⋅+⋅⋅=
×⋅∇+×⋅∇
******
****
****
******
******
**
µµζζ
ξξεε
ω
µµζζξξεεω
µζξεω
µζξεω
( ) ( ) ( ) ( )[ ] ( ) ( ) ( ) ( )[ ]ωωωωωω ,,,,
4
1
,,Re
2
1
,, **
rHrErHrErHrEaltrHtrES ×+×=×=×=
We found the time average of the Poynting vector
We see that
( ) ( )[ ] [ ]
( ) ( )mmee
HH
HH
JHJHJEJE
H
Ej
HEHEHES
⋅+⋅−⋅+⋅−
⋅
−−
−−
−⋅=×⋅∇+×⋅∇=⋅∇
****
****
4
1
4
1
44
1
µµζζ
ξξεεω
Energy Flux and Poynting Vector for a Bianisotropic Medium (continue – 2)
68. 68
SOLO ELECTROMAGNETICS
Let integrate the mean value of the Poynting vector over the volume V
[ ]
( ) ( )
( ) ( )[ ]
( ) ∫∫
∫
∫∫
∫∫
→→
⋅=⋅×+×=
×⋅∇+×⋅∇=
⋅+⋅−⋅+⋅−
⋅
−−
−−
−⋅=⋅∇
SS
Gauss
V
V
mm
V
ee
V
HH
HH
V
dSnSdSnHEHE
dVHEHE
dVJHJHdVJEJE
dV
H
Ej
HEdVS
11
4
1
4
1
4
1
4
1
4
**
1
**
****
**
µµζζ
ξξεεω
( ) ( )[ ] [ ]
( ) ( )mmee
HH
HH
JHJHJEJE
H
Ej
HEHEHES
⋅+⋅−⋅+⋅−
⋅
−−
−−
−⋅=×⋅∇+×⋅∇=⋅∇
****
****
4
1
4
1
44
1
µµζζ
ξξεεω
Energy Flux and Poynting Vector for a Bianisotropic Medium (continue – 3)
69. 69
SOLO ELECTROMAGNETICS
We recognize the following
−−
−−
−=
HH
HH
j
µµζζ
ξξεεω
4
G
mediumlosslessundefinite
mediumpassivedefinitenegative
mediumactivedefinitepositive
⇒
⇒
⇒
G
G
G
[ ]
( ) ( )∫∫
∫∫
⋅+⋅−⋅+⋅−
⋅
−−
−−
−⋅=⋅
→
V
mm
V
ee
V
HH
HH
S
dVJHJHdVJEJE
dV
H
Ej
HEdSnS
****
**
4
1
4
1
4
1
µµζζ
ξξεεω
[ ] dV
H
Ej
HE
V
∫
⋅
−−
−−
−⋅
**
**
**
4 µµζζ
ξξεεω
( )∫ ⋅+⋅
V
ee dVJEJE **
4
1
( )∫ ⋅+⋅
V
mm dVJHJH **
4
1
∫
→
⋅
S
dSnS 1
Time average of the Radiated
Energy through S (Irradiance)
Time average of Electromagnetic
Energy in V
Time average of
Joule Energy in V
Time average of
Fictious Joule
Energy in V
Energy Flux and Poynting Vector for a Bianisotropic Medium (continue – 4)
Return to Table of Content
70. 70
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
0
0
0
0
m
e
m
e
B
D
J
t
B
E
J
t
D
H
ρ
ρ
=⋅∇
=⋅∇
−
∂
∂
−=×∇
+
∂
∂
=×∇
( )
⋅−
=
⋅−
==
rs
c
n
tj
s
c
n
k
rktj
eEeEE
ˆ
0
ˆ
0
ω
ω
ω
ωω
ωω
j
t
eje
t
rs
c
n
tjrs
c
n
tj
→
∂
∂
⇒=
∂
∂
⋅−
⋅−
ˆˆ
sjks
c
n
jes
c
n
je
k
rs
c
n
tjrs
c
n
tj
ˆˆˆ
ˆˆ
−=−→∇⇒−=∇
⋅−
⋅−
ωω
ωω
0ˆ
0ˆ
ˆ
ˆ
=⋅
=⋅
=×
−=×
Bs
Ds
BEs
c
n
DHs
c
n
( )
( )DEBH
tt
D
E
t
B
H
HEEHHES
HB
ED
⋅+⋅
∂
∂
−=
∂
∂
⋅−
∂
∂
⋅−=
×∇⋅−×∇⋅=×⋅∇=⋅∇
=
⋅= 2
1µ
ε
( ) emUDEBHS
k
Ss
c
n
=⋅+⋅=⋅=⋅
2
1
ˆ
ω
Maxwell’s
Symmetric Equations
Planar
Monochromatic Wave
0
0
=⋅
=⋅
=×
−=×
Bk
Dk
BEk
DHk
ω
ω
ωj
t
→
∂
∂
s
c
n
j ˆω−→∇
ωj
t
→
∂
∂
kj
−→∇
vector phasor
vector phasor
c
n
k ω=:
71. 71
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
0ˆ
0ˆ
ˆ
ˆ
=⋅
=⋅
=×
−=×
Bs
Ds
BEs
c
n
DHs
c
n
dyadicsxwhere
H
E
B
D
33,,, µζξε
µζ
ξε
=
HHIB
ED
µµ
ε
=⋅=
⋅=
For Anisotropic Electric Media
the Linear Constitutive Relations are
Planar Waves in an Source-less Media
The most general form of Linear Constitutive Relations is:
HES ×= Poynting Vector
B
D
pv
E
H
HES
×=α
α
k
ev
PlanarWaves
( ) DHs
c
n
Bs
c
n
Ess
c
n
µµ −=×=×=××
ˆˆˆˆ
2
( ) ( )[ ]EssE
c
n
Ess
c
n
D ⋅−
=××
−= ˆˆ
1
ˆˆ
1
22
µµ SDEs ,,,ˆ
are coplanar
and normal to H
I
µµζξε === ,0,
72. 72
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
B
D
pv
E
H
HES
×=α
α
k
ev
PlanarWaves( ) ( )[ ]EssE
c
n
Ess
c
n
D ⋅−
=××
−= ˆˆ
1
ˆˆ
1
22
µµ
SDEs ,,,ˆ
are coplanar
and normal to H
( ) DEnEsDsDE
c
n
DD
c
⋅=
⋅⋅−⋅
=⋅
=
2
0
1
0
2 02
ˆˆ
1
ε
µ
µε
DE
DD
n
⋅
⋅
=
0
2 1
ε
( )
( )
( )
( )( )2222
2
2
2
2
2
ˆ
DEDED
DDEED
D
DE
E
D
DDE
E
D
D
D
D
EE
D
D
D
D
EE
s
⋅−
⋅−
=
⋅
−
⋅
−
=
⋅−
⋅−
=
( )
( )
( )
( )( )2222
2
2
2
2
2
:
DEDEE
EDEDE
E
DE
D
E
DDE
D
E
E
E
E
DD
E
E
E
E
DD
S
S
t
⋅−
⋅−
−=
⋅
−
⋅
−
−=
⋅−
⋅−
−==
If and are not collinear:DE
73. 73
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Phase Velocity, Energy (Ray) Velocity
The phase of the field is given by
⋅−=⋅−= rs
c
n
trkt
ˆωωφ
For a constant phase front we have
⋅−=⋅−=⋅−== rds
c
n
dtrdskdtrdkdtd
ˆˆ0 ωωωφ
s
n
c
s
kdt
rd
v
srr
const
p
ˆˆ
ˆ
===
=
=
ω
φ
Phase Velocity B
D
pv
E
H
HES
×=α
α
k
ev
PlanarWaves
n
c
ktd
rd
s ==⋅
ω
ˆ
n
c
S
S
vs e =⋅ˆ
( ) α
α
cosˆ
ˆ
cos
p
S
Ss
e
v
Ss
S
n
c
v
⋅
=
=
⋅
=
Define the phase velocity as
Define the energy flow velocity in the Poynting vector direction as
S
S
vSv ee =
→
1
( ) emUDEBHS
k
Ss
c
n
=⋅+⋅=⋅=⋅
2
1
ˆ
ω
( ) em
ee
U
S
S
Ssn
c
S
S
vv =
⋅
==
ˆ
1
Energy (Ray) Velocity
The electro-magnetic energy propagates along the Poynting vector .
For anisotropic media the Poynting vector is not collinear with .k
HES ×=
Return to Table of Content
s
c
n
k ˆω=
Electromagnetic Energy Density
74. 74
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
BEk
DHk
ω
ω
=×
−=×
HHIB
ED
µµ
ε
=⋅=
⋅=
Wave Equation
( ) EDHkBkEkk
EDDHkHBBEk
⋅−=−=×=×=××
⋅=−=×==×
εµωµωµωω
εωµω
22
2222
0
0
0
ˆ kkkkkk
kk
kk
kk
k
k
k
k
s
s
s
kskk zyx
xy
xz
yz
z
y
x
z
y
x
=++=⋅
−
−
−
=×⇒
=
==
( )
( )
( )
( )
+−
+−
+−
=
−
−
−
−
−
−
=××
22
22
22
0
0
0
0
0
0
yxzyzx
zyzxyx
zxyxzy
xy
xz
yz
xy
xz
yz
kkkkkk
kkkkkk
kkkkkk
kk
kk
kk
kk
kk
kk
kk
=
z
y
x
ε
ε
ε
ε
00
00
00
=
=
2
2
2
0
0
0
0
0
0
2
2
00
00
00
00
00
00
c
n
c
n
c
n
z
x
x
z
y
x
ω
ω
ω
εµ
εµ
εµ
εµ
εµ
εµ
εµ
εµ
εµω
εωµ
In principal dielectric axes:
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
( ) 02
=⋅+×× EEkk εµω
( ) 021
=+×× −
DDkk µωε
or
75. 75
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave Equation (continue – 1)
( ) 02
=⋅+×× EEkk εµω
( )
( )
( )
0
22
2
22
2
22
2
=
+−
+−
+−
z
y
x
yx
z
zyzx
zyzx
y
yx
zxyxzy
x
E
E
E
kk
c
n
kkkk
kkkk
c
n
kk
kkkkkk
c
n
ω
ω
ω
A nonzero solution exists only when
( )
( )
( )
0det
22
2
22
2
22
2
=
+−
+−
+−
yx
z
zyzx
zyzx
y
yx
zxyxzy
x
kk
c
n
kkkk
kkkk
c
n
kk
kkkkkk
c
n
ω
ω
ω
76. 76
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave Equation (continue – 2)
( )
( )
( )
+−
+−
+−
=
+−
+−
+−
++=
22
2
22
2
22
2
22
2
22
2
22
2
2222
det
z
z
zyzx
zyy
y
yx
zxyxx
x
kkkk
yx
z
zyzx
zyzx
y
yx
zxyxzy
x
kk
c
n
kkkk
kkkk
c
n
kk
kkkkkk
c
n
kk
c
n
kkkk
kkkk
c
n
kk
kkkkkk
c
n
zyx
ω
ω
ω
ω
ω
ω
We obtain
−−
−−
−+
−+
−
−
+−= 2
2
22
222
2
22
222
2
22
22
2
22
22
2
22
2
2
22
22
2
22
k
c
n
kkk
c
n
kkk
c
n
kk
c
n
kk
c
n
k
c
n
kk
c
n y
zx
z
yx
y
z
z
y
zy
x
x
ωωωωωωω
02
2
22
2
2
22
22
2
22
2
2
22
22
2
22
2
2
22
22
2
22
2
2
22
2
2
22
=
−
−+
−
−+
−
−+
−
−
−= k
c
n
k
c
n
kk
c
n
k
c
n
kk
c
n
k
c
n
kk
c
n
k
c
n
k
c
n yx
z
zx
y
zy
x
zyx
ωωωωωωωωω
Divide by (assumed nonzero!!)
−
−
−− 2
2
22
2
2
22
2
2
22
k
c
n
k
c
n
k
c
n zyx ωωω
1
2
22
2
2
2
22
2
2
2
22
2
2
=
−
+
−
+
−
c
n
k
k
c
n
k
k
c
n
k
k
z
z
y
y
x
x
ωωω
This is a quadratic equation
of k2
(k6
terms drop – next
slide). For each set sx, sy, sz it
yields two solutions for k2
:
k1
2
and k2
2
=
z
y
x
z
y
x
s
s
s
k
k
k
k
2
2
22
2
2
2
22
2
2
2
22
2
2
1
k
c
n
k
s
c
n
k
s
c
n
k
s
z
z
y
y
x
x
=
−
+
−
+
−
ωωω
( )skkk ˆ,, 21
ε
=
77. 77
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
02
2
22
2
2
22
222
2
22
2
2
22
222
2
22
2
2
22
222
2
22
2
2
22
2
2
22
=
−
−+
−
−+
−
−+
−
−
− k
c
n
k
c
n
skk
c
n
k
c
n
skk
c
n
k
c
n
skk
c
n
k
c
n
k
c
n yx
z
zx
y
yz
x
zyx
ωωωωωωωωω
( ) ( )
( ) ( ) ( ) 02222
4
4
4222
2
2
622222
4
4
4222
2
2
622222
4
4
4222
2
2
62
222
6
6
2222222
4
4
4222
2
2
6
=++−+++−+++−+
+++−+++−
ksnn
c
ksnn
c
ksksnn
c
ksnn
c
ksksnn
c
ksnn
c
ks
nnn
c
knnnnnn
c
knnn
c
k
zyxzyxzyzxyzxyxzyxzyx
zyxzyzxyxzyx
ωωωωωω
ωωω
( ) ( ) ( ) ( )[ ] 0111
222
6
6
2222222222
4
4
4222222
2
2
=+−+−+−−++ zyxxzyyzxzyxzzyyxx
nnn
c
ksnnsnnsnn
c
ksnsnsn
c
ωωω
This is a quadratic equation of k2
.
For each set sx, sy, sz it yields two solutions for k2
: k1
2
and k2
2
( )skkk ˆ,, 21 ε
=
2
2
22
2
2
2
22
2
2
2
22
2
2
1
k
c
n
k
s
c
n
k
s
c
n
k
s
z
z
y
y
x
x
=
−
+
−
+
−
ωωω
02
2
22
2
2
22
22
2
22
2
2
22
22
2
22
2
2
22
22
2
22
2
2
22
2
2
22
=
−
−+
−
−+
−
−+
−
−
− k
c
n
k
c
n
kk
c
n
k
c
n
kk
c
n
k
c
n
kk
c
n
k
c
n
k
c
n yx
z
zx
y
zy
x
zyx
ωωωωωωωωω
=
z
y
x
z
y
x
s
s
s
k
k
k
k
Wave Equation (continue – 2a)
1
222
=++ zyx sss
78. 78
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave Equation (continue – 3)
( )
( )
( )
0
22
2
22
2
22
2
=
+−
+−
+−
z
y
x
yx
z
zyzx
zyzx
y
yx
zxyxzy
x
E
E
E
kk
c
n
kkkk
kkkk
c
n
kk
kkkkkk
c
n
ω
ω
ω
A solution (self-mode) is:
( ) ( )
( ) ( )
( ) ( ) 0
0
0
222
2
222
2
222
2
=+++
++−
=+++
++−
=+++
++−
⋅
⋅
⋅
Ek
zzyyxxzzzyx
z
Ek
zzyyxxyyzyx
y
Ek
zzyyxxxxzyx
x
EkEkEkkEkkk
c
n
EkEkEkkEkkk
c
n
EkEkEkkEkkk
c
n
ω
ω
ω
−
−
−
2
2
2
2
2
2
k
c
n
k
k
c
n
k
k
c
n
k
z
z
y
y
x
x
ω
ω
ω
( )Ek ⋅−
( )
( )
( )
−
⋅
−
⋅
−
⋅
−=
2
2
2
2
2
2
k
c
n
Ekk
k
c
n
Ekk
k
c
n
Ekk
E
E
E
z
z
y
y
x
x
z
y
x
ω
ω
ω
In principal dielectric axes
Return to Table of Content
79. 79
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface
The above equation can be represented by a three-dimensional surface in k space.
( )
( )
( )
0det
22
2
22
2
22
2
=
+−
+−
+−
yx
z
zyzx
zyzx
y
yx
zxyxzy
x
kk
c
n
kkkk
kkkk
c
n
kk
kkkkkk
c
n
ω
ω
ω
The understand how this surface look let find the intersection of the surface with kz = 0.
( )
( ) 0
00
0
0
det
222
2
2
2
22
2
22
2
2
2
2
2
=
−
−
−
+−
=
+−
−
−
yxx
y
y
x
yx
z
yx
z
x
y
yx
yxy
x
kkk
c
n
k
c
n
kk
c
n
kk
c
n
k
c
n
kk
kkk
c
n
ωωω
ω
ω
ω
80. 80
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface (continue – 1)
The intersection of the surface with kz = 0 is given by two equations, derived from:
( ) 0
22
2
222
2
2
2
=
+−
−
−
−
yx
z
yxx
y
y
x
kk
c
n
kkk
c
n
k
c
n ωωω
2
22
=+
c
n
kk z
yx
ω
( ) ( )
1
//
22
=+
cn
k
cn
k
x
y
y
x
ωω
( )
0
00
0
0
22
2
2
2
2
2
=
+−
−
−
z
y
x
yx
z
x
y
yx
yxy
x
E
E
E
kk
c
n
k
c
n
kk
kkk
c
n
ω
ω
ω
=
=
zz
y
x
EE
E
E
E 0
0
2
−
−
=
=
0
2
2
1 y
x
yx
z
y
x
k
c
n
kk
E
E
E
E
ω
021 =⋅ EE
Ellipse
The electric fields corresponding to those two solutions are:
on Ellipse
on Circle
Since the coefficients of the electric fields are real the two
solutions represents two linear polarized planar waves.
Circle
81. 81
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface (continue -2)
Intersection of the surface with kz = 0,
are a circle and an ellipse in kx, ky plane.
2
22
=+
c
n
kk z
yx
ω
( ) ( )
1
//
2
2
2
2
=+
cn
k
cn
k
x
y
y
x
ωω
Intersection of the surface with ky = 0,
are a circle and an ellipse in kx, kz plane.
2
22
=+
c
n
kk
y
zx
ω
( ) ( )
1
//
2
2
2
2
=+
cn
k
cn
k
x
z
z
x
ωω
Intersection of the surface with kx = 0,
are a circle and an ellipse in ky, kz plane.
2
22
=+
c
n
kk x
zy
ω
( ) ( )
1
//
2
2
2
2
=+
cn
k
cn
k
y
z
z
y
ωω
Suppose nx < ny < nz.
( ) 0
222
2
2
2
22
2
=
−
−
−
+−
yxx
y
y
x
yx
z
kkk
c
n
k
c
n
kk
c
n ωωω
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
82. 82
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface (continue – 3)
The complete k surface is double;
that is, it consists of an inner shell
and an outer shell.
For any given direction of the vector
k, there are two possible values for the
wave-number k (eigenmodes). Therefore
are also two values for the phase velocity.
From the figure we can see that the inner
and outer shells of the k surface intersect
at four points in each quadrant of the
kx, kz plane (for nx<ny<nz). Those points
define two directions for which the two
values of k are equal. Those two directions
are called Optical Axes.
The structure of an anisotropic medium
permits two monochromatic plane waves
that are polarized orthogonally with
respect to each other.
If nx,ny and nz are different the crystal has
two optical axes and is said to be biaxial.
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
nx < ny < nz.
83. 83
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface (continue -4)
Let compute the Optical Axis direction.
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
We can see that the Optical Axis is in
x, z plane, therefore
=
=
=
δ
δ
ω
cos
0
sin
c
n
s
s
s
k
k
k
k
k OA
OAz
y
x
OA
OAz
y
x
OA
2
22
=+
c
n
kk
y
zx
ω
( ) ( )
1
//
2
2
2
2
=+
cn
k
cn
k
x
z
z
x
ωω
22
=
c
n
c
n yOA
ωω 1
cossin
2
22
2
22
=+
x
OA
z
OA
n
n
n
n δδ
must be at the intersection ofOAk
and
yOA nn =
( )
1
coscos1
2
22
2
22
=+
−
x
y
z
y
n
n
n
n δδ
22
22
2
cos −−
−−
−
−
=
zx
zy
OA
nn
nn
δ 22
22
2
sin −−
−−
−
−
=
zx
yx
OA
nn
nn
δ 22
22
2
tan −−
−−
−
−
=
zy
yx
OA
nn
nn
δ
If δ is less than 45º, the crystal is said to be a positive biaxial crystal.
If δ is greater than 45º, the crystal is said to be a negative biaxial crystal.
nx < ny < nz.
−
−
±= −−
−−
−
22
22
1
2,1
sin
zx
yx
OA
nn
nn
δ
84. 84
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface (continue -5)
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===nx < ny < nz.
85. 85
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Double Refraction at a Birefringent Crystal Boundary
( ) 0ˆ
=−× ti
kkn
At the Crystal Boundary defined by the normal
the following condition must be satisfied
nˆ
The refracted wave is, in general, a mixture of
two eigenmodes
( ) ( )222111 ,,, sn
c
ksn
c
k
ε
ω
ε
ω
==
We can write
( ) ( ) 222111
sin,sin,sin θεθεθ skskk ii
==
This looks like Snell’s Law but k1 and k2 are not constant, and we must add the
quadratic equation in k2
:
( ) ( ) ( ) ( )[ ] 0111
222
6
6
2222222222
4
4
4222222
2
2
=+−+−+−−++ zyxxzyyzxzyxzzyyxx nnn
c
ksnnsnnsnn
c
ksnsnsn
c
ωωω
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
86. 86
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface (continue – 6)
If two of the refraction indices are equal
the crystal has one optical axis and is said
to be uniaxial.
zyx εεε ≠=nx = ny =no≠ nz=ne
For each set sx, sy, sz it yields two solutions
for k2
: k1 and k2 ( )skkk ˆ,, 21
ε
=
The quadratic equation of k2
is:
2
2
22
2
2
2
22
2
2
11
k
c
n
k
s
c
n
k
s
e
z
o
z
=
−
+
−
−
ωω
( )[ ] ( ) ( )[ ] 0111
24
6
6
222222
4
4
42222
2
2
=+++−−+− eozezoozezo nn
c
ksnsnn
c
ksnsn
c
ωωω
( ) ( ) ( ) ( )[ ] 0111
222
6
6
2222222222
4
4
4222222
2
2
=+−+−+−−++ zyxxzyyzxzyxzzyyxx nnn
c
ksnnsnnsnn
c
ksnsnsn
c
ωωω
nx = ny =no≠ nz=ne
Uniaxial Crystals
One other way is to substitute in:
87. 87
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Wave-Vector Surface (continue – 7)
zyx εεε ≠=nx = ny =no≠ nz=ne
( )[ ] ( ) ( )[ ] 0111
24
6
6
222222
4
4
42222
2
2
=+++−−+− eozezoozezo
nn
c
ksnsnn
c
ksnsn
c
ωωω
( )( ) 01
2
2
2
22222
2
2
2
2
22
=
−−−+
− oeozoe n
c
kknnsn
c
kn
ωω
( )[ ] 01
22
2
2
222222
2
2
2
=
−+−
− eoezozo nn
c
knsnsn
c
k
ωω
The Wave-Vector surface decomposes into two separate shells
0
2
2
2
2
=− on
c
k
ω
( )[ ] 0
22
2
2
222222
=−++ eoezoyx
nn
c
knsnss
ω
0
2
2
2
222
=−++ ozyx n
c
kkk
ω
Spherical surface
01
2
2
2
2
2
2
2
22
=−+
+
o
z
e
yx
n
c
k
n
c
kk
ωω
Ellipsoid of Revolution
surface
These two surfaces are tangent along the z axis.
Uniaxial Crystals (continue – 1)
Return to Table of Content
88. 88
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Double Refraction at a Uniaxial Crystal Boundary
For the Uniaxial Crystal is easy to solve the Boundary condition graphically:
( ) eeooii skkk θεθθ sin,sinsin 2
==
The Wave-Vector surface decomposes into two separate shells:
• the sphere of the ordinary wave with
• the ellipsoid of extraordinary wave with
.constko =
( )2, ske
ε
is found graphically using the equality: Snell’s Lawooii kk θθ sinsin =o
k
The intersection of the normal to the boundary from the
end with the ellipse defines the direction of
ek
o
k
The intersection of the plane defined by and passing
through the common centers of the sphere and the ellipsoid will
give a circle and an ellipse, respectively.
nki
,
ii
k θsin
ik
ok
i
θ
oθ
Intersection of
normal surface with
plane of incidence
in
ii
k θsin
Uniaxial
Crystal
Incident
ray
n
Optical
Axis
oE
eo nn >
96. 96
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Crystal Types (continue – 3)
A.Mermin, “Solid State Physics”,
Holt, Reinhart and Winston, 1976,
p.122
Return to Table of Content
97. 97
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Orthogonality Properties of the Eigenmodes
Assume the two monochromatic waves corresponding to a given direction
are defined by and
sˆ
1111 ,,, nDEH
2222 ,,, nDEH
Start with Lorentz Reciprocity Theorem
Use
HB
BEs
c
n
µ=
=×
ˆ
Es
c
n
H ×= ˆ
µ
( )[ ] ( )[ ]12
2
21
1
ˆˆˆˆ EsEs
c
n
EsEs
c
n
××⋅=××⋅
µµ
( ) ( ) ( ) ( )12
2
21
1
ˆˆˆˆ EsEs
c
n
EsEs
c
n
×⋅×=×⋅×
µµ
( ) ( )1221
ˆˆ HEsHEs ×⋅=×⋅
Since we have21 nn ≠
( ) ( ) 0ˆˆ 21 =×⋅× EsEs ( ) ( ) 0ˆˆ 1221 =×⋅=×⋅ HEsHEs
( ) ( )1221 HEHE
×⋅∇=×⋅∇
s
c
n
j ˆω−→∇
0=⋅=⋅ sHEH
98. 98
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Orthogonality Properties of the Eigenmodes (continue – 1)
We obtain
0ˆˆˆˆ 221121212121212121
=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅ HEHEHsHsDsDsEEEDDEDDHH
( ) ( ) 0ˆˆ 1221 =×⋅=×⋅ HEsHEs
( ) ( )
( ) ( ) 0ˆˆ
0ˆˆ
21
1
2
21
2
ˆ
2121
21
1
ˆ
2121
2
2
2
1
1
1
11
=⋅=⋅=×⋅−=×⋅
=⋅=⋅×=×⋅
−
−=×
=×
=
DD
n
c
DE
n
c
HsEHEs
HH
n
c
HEsHEs
D
n
c
Hs
B
n
c
Es
HB
ε
µ
µ
( ) ( )
( ) ( ) 0ˆˆ
0ˆˆ
12
1
1
12
1
ˆ
1212
12
2
ˆ
1212
1
1
1
2
2
2
22
=⋅=⋅=×⋅−=×⋅
=⋅=⋅×=×⋅
−
−=×
=×
=
DD
n
c
DE
n
c
HsEHEs
HH
n
c
HEsHEs
D
n
c
Hs
B
n
c
Es
HB
ε
µ
µ
99. 99
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Orthogonality Properties of the Eigenmodes (continue – 2)
We obtained
The two solutions correspond to two different possible linear polarizations of a
wave propagating in direction and these two solutions have mutually
orthogonal polarizations.
sˆ
0ˆˆˆˆ 221121212121212121
=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅ HEHEHsHsDsDsEEEDDEDDHH
Return to Table of Content
100. 100
SOLO ELECTROMAGNETICS
Phase Velocity, Energy (Ray) Velocity for Planar Waves
The phase of the field is given by
⋅−=⋅−= rs
c
n
trkt
ˆωωφ
For a constant phase front we have
⋅−=⋅−=⋅−== rds
c
n
dtrdskdtrdkdtd
ˆˆ0 ωωωφ
s
n
c
s
kdt
rd
v
srr
const
p
ˆˆ:
ˆ
===
=
=
ω
φ
Phase Velocity B
D
pv
E
H
HES
×=α
α
k
ev
PlanarWaves
n
c
ktd
rd
s ==⋅
ω
ˆ
n
c
S
S
vs e =⋅ :ˆ
( ) α
α
cosˆ
cos
ˆ
p
S
Ss
e
v
Ss
S
n
c
v
=
⋅
=
⋅
=
Define the phase velocity as
Define the energy flow velocity in the Poynting vector direction as
S
S
vSv ee =
→
1
( ) emUDEBHS
k
Ss
c
n
=⋅+⋅=⋅=⋅
2
1
ˆ
ω
( ) em
ee
U
S
S
Ssn
c
S
S
vv =
⋅
==
ˆ
1
:
Energy (Ray) Velocity
The electro-magnetic energy propagates along the Poynting vector .
For anisotropic media the Poynting vector is not collinear with .k
HES ×=
Return to Table of Content
101. 101
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Ray-Velocity Surface
We defined the Energy-Ray Velocity as
Let compute
( ) HDHEDEH
U
DHE
U
Dv
emUemem
e =
⋅−
⋅=××=×
0
11
( ) ( ) DEHHEHEH
U
HHE
U
HvDvv
emUemem
eee
1
/0
1111 −
−=−=
⋅−
⋅=××=×=×× ε
µµµ
In principal dielectric axes:
=
=−
2
2
2
2
2
2
1
00
00
00
1
00
0
1
0
00
1
1
z
y
x
z
y
x
n
c
n
c
n
c
εµ
εµ
εµ
ε
µ
( ) em
ee
U
S
S
Ssn
c
S
S
vv =
⋅
==
ˆ
1
:
102. 102
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Ray-Velocity Surface (continue – 1)
We can write ( ) 0
1 1
=+×× −
DDvv ee ε
µ
as
( )
( )
( )
0
22
2
22
2
22
2
=
+−
+−
+−
z
y
x
eyex
z
ezeyezex
ezeyezex
y
eyex
ezexeyexezey
x
D
D
D
vv
n
c
vvvv
vvvv
n
c
vv
vvvvvv
n
c
We obtain non-zero solutions only when
( )
( )
( )
0det
22
2
22
2
22
2
=
+−
+−
+−
eyex
z
ezeyezex
ezeyezex
y
eyex
ezexeyexezey
x
vv
n
c
vvvv
vvvv
n
c
vv
vvvvvv
n
c
103. 103
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Intersection of the surface with vez = 0,
are a circle and an ellipse in vex, vey plane.
2
22
=+
z
eyex
n
c
vv
( ) ( )
1
//
2
2
2
2
=+
x
ey
y
ex
nc
v
nc
v
Intersection of the surface with vey = 0,
are a circle and an ellipse in vex, vez plane.
2
22
=+
y
ezex
n
c
vv
( ) ( )
1
//
2
2
2
2
=+
x
z
z
ex
nc
k
nc
v
Intersection of the surface with vex = 0,
are a circle and an ellipse in vey, vez plane.
2
22
=+
x
ezey
n
c
vv
( ) ( )
1
//
2
2
2
2
=+
y
ez
z
ey
nc
v
nc
v
Suppose nx < ny < nz.
Ray-Velocity Surface (continue – 2)
The previous equation has the same structure as the Wave-Vector Surface, therefore
can be represented by a three-dimensional surface in ve space. vex, vey and vez are the
components of ve in the principal axes of the dielectric.
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
104. 104
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
nx < ny < nz.
The complete ve surface is double;
that is, it consists of an inner shell
and an outer shell.
For any given direction of the vector
ve, there are two possible values for the
energy-ray velocity ve (eigenmodes):
ve1 and ve2.
From the figure we can see that the inner
and outer shells of the ve surface intersect
at four points in each quadrant of the
vex, vez plane (for nx<ny<nz). Those points
define two directions for which the two
values of ve are equal. Those directions are
called Ray Axes and are distinct from the
Optic Axes of the dielectric.
Ray-Velocity Surface (continue – 3)
105. 105
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Let compute the Ray Axis direction.
We can see that the Ray Axis is in
x, z plane, therefore
==
=
→
RA
RA
RA
RARAe
RAez
ey
ex
RAe
n
c
Sv
v
v
v
v
δ
δ
cos
0
sin
1
2
22
=+
y
ezex
n
c
vv
( ) ( )
1
//
2
2
2
2
=+
x
ez
z
ex
nc
v
nc
v
22
=
yRA n
c
n
c 1
cossin
2
22
2
22
=+
RA
RAx
RA
RAz
n
n
n
n δδ
must be at the intersection ofRAev
and
yRA nn =
( ) 1
coscos1
2
22
2
22
=+
−
y
RAx
y
RAz
n
n
n
n δδ
22
22
2
cos
zx
zy
RA
nn
nn
−
−
=δ 22
22
2
sin
zx
yx
RA
nn
nn
−
−
=δ 22
22
2
tan
zy
yx
RA
nn
nn
−
−
=δ
−
−
±= −
22
22
1
2,1
sin
zx
yx
RA
nn
nn
δ
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
Ray-Velocity Surface (continue – 4)
RA
x
z
yz
xy
x
z
OA
n
n
nn
nn
n
n
δδ 2
2
2
22
22
2
2
2
tantan =
−
−
=
Ray Axes are distinct from
Optical Axes.
106. 106
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
( )
( )
( )
+−
+−
+−
=
+−
+−
+−
++=
22
2
22
2
22
2
22
2
22
2
22
2
2222
det
eze
z
ezeyezex
ezeyeye
y
eyex
ezexeyexexe
x
vvvv
eyex
z
ezeyezex
ezeyezex
y
eyex
ezexeyexezey
x
vv
n
c
vvvv
vvvv
n
c
vv
vvvvvv
n
c
vv
n
c
vvvv
vvvv
n
c
vv
vvvvvv
n
c
ezeyexe
We obtain
−−
−−
−+
−+
−
−
+−=
2
2
2
222
2
2
222
2
2
22
2
2
22
2
2
2
2
2
22
2
2
e
y
ezexe
z
eyexe
y
eze
z
eye
z
e
y
exe
x
v
n
c
vvv
n
c
vvv
n
c
vv
n
c
vv
n
c
v
n
c
vv
n
c
0
2
2
2
2
2
2
22
2
2
2
2
2
22
2
2
2
2
2
22
2
2
2
2
2
2
2
2
=
−
−+
−
−+
−
−+
−
−
−= e
y
e
x
eze
z
e
x
eye
z
e
y
exe
z
e
y
e
x
v
n
c
v
n
c
vv
n
c
v
n
c
vv
n
c
v
n
c
vv
n
c
v
n
c
v
n
c
Divide by (assumed nonzero!!(
−
−
−−
2
2
2
2
2
2
2
2
2
e
z
e
y
e
x
v
n
c
v
n
c
v
n
c
1
2
2
2
2
2
2
2
2
2
2
2
2
=
−
+
−
+
−
z
e
ez
y
e
ey
x
e
ex
n
c
v
v
n
c
v
v
n
c
v
v
Ray-Velocity Surface (continue – 5(
Return to Table of Content
107. 107
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid
The electric energy density is given by: ∗∗−∗
⋅⋅=⋅⋅=⋅= EEDDDEUe εε
2
1
2
1
2
1 1
Let find the Surfaces of Equal Energy expressed in the principal dielectric axes:
z
z
y
y
x
x
e
DDD
DDU
εεε
ε
222
1
2 ++=⋅⋅= ∗−
We have: ( ) ( ) zyxin iii ,,// 00
2
=== εεεµεµ
Define: ezeyex UEzUEyUEx 2/:2/:2/: 000 εεε ===
The surfaces of equal energy expressed in the principal dielectric axes are:
1
/1/1/1
2
2
2
2
2
2
=++
zyx n
z
n
y
n
x
Fresnel’s Ellipsoid
0ˆˆˆˆ 221121212121212121
=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅ HEHEHsHsDsDsEEEDDEDDHH
We found that the two eigenmodes, of each
direction , must satisfy:
s
222
2 zzyyxxe EEEEEU εεεε ++=⋅⋅= ∗
108. 108
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 1(
The electric energy density is given by: ∗∗−∗
⋅⋅=⋅⋅=⋅= EEDDDEUe εε
2
1
2
1
2
1 1
z
z
y
y
x
x
e
DDD
DDU
εεε
ε
222
1
2 ++=⋅⋅= ∗−
We have: ( ) ( ) zyxin iii ,,// 00
2
=== εεεµεµ
Define: 000 2/:2/:2/: εεε ezeyex UDzUDyUDx ===
The surfaces of equal energy expressed in the principal dielectric axes are:
12
2
2
2
2
2
=++
zyx n
z
n
y
n
x
Index Ellipsoid,
Optical Indicatrix,
Reciprocal Ellipsoid
0ˆˆˆˆ 221121212121212121
=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅=⋅ HEHEHsHsDsDsEEEDDEDDHH
We found that the two eigenmodes, of each
direction , must satisfy:
s
222
2 zzyyxxe EEEEEU εεεε ++=⋅⋅= ∗
Let find the Surfaces of Equal Energy expressed in the principal dielectric axes:
109. 109
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 2(
Since we found that the index ellipsoid is used to find the two indexes
of refraction and the two corresponding directions that are in the plane
normal to that passes through ellipsoid center O and defines the ellipse.
0ˆˆ 21 =⋅=⋅ DsDs
21 DandD
sˆ
Sπ
Assume that is one of
the expected solutions.
0
2/ εe
UDOP =
→
The normal at P to the ellipsoid PV is:
E
U
z
D
y
D
x
D
U
z
z
y
y
x
x
ez
z
y
y
x
x
e
zyx
PV
2
111
2
111
00
0
ε
εεε
ε
εεε
ε
=
++=
++=
∧∧∧
∧∧∧→
Since are coplanar PV is in the
plane defined by and sˆDπ D
sED
,,
The plane tangent to ellipsoid at P
is normal to PV ( (, intersects plane
along PT that will be normal to and
, therefore it gives direction.
Tπ
E
E
H
Sπ
sˆ 0ˆˆ 221121 =⋅=⋅=⋅=⋅ HEHEHsHs
110. 110
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 3(
PT is at the intersection of the tangent plane to the ellipsoid at P to the plane
normal to and containing PO. Therefore PT is tangent to the ellipse containing PO.
Tπ Sπ
sˆ
- Since PT is in , it is normal toSπ sˆ
E
- Since PT is in the tangent plane to
the ellipsoid, it is normal to PV ( (
Tπ
sˆ
H
EH- Since is also normal to and
PT defines the direction of
is also normal toH D
The tangent to an ellipse is only normal
to the radius vector if it is one of the
axes of the ellipse.
We conclude that the directions of
are the directions of the axes of the
ellipse obtained by the intersection of
the ellipsoid with the plane normal
to .
21 DandD
sˆ
111. 111
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 4(
To find for the propagation direction we find the ellipse obtained by the
intersection of the plane normal to , at the origin O, with the Index Ellipsoid.
21 DandD sˆ
sˆSπ
21
DandD are in the direction of ellipsoid axes, and therefore perpendicular to
each other
is on the normal to ellipsoid
at OP = and in the plane
of and . In the same plane
and normal to is
E
sˆ
E
Dπ
D
Dπ
HE
HE
S
×
×
=
→
1
112. 112
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 5( 12
2
2
2
2
2
=++
zyx n
z
n
y
n
xnx < ny < nz.
For the propagation direction of the Optical Axis
the intersection of the plane normal to ,
at the origin O, with the Index Ellipsoid is a Circle.
OAsˆSπ
OAsˆ
1
D
21 DandD are in any direction on this circle, and therefore
for any we can find the perpendicular to it.2
D
Conical Refraction on the Optical Axis
We want to find the direction of vectors. E
We have: [ ] ET
E
E
E
EsDs
z
y
x
zxOAOA ⋅=
⋅=⋅⋅=⋅=
δεδεε cos0sinˆˆ0
where: [ ]T
zxT δεδε cos0sin:=
=
δ
δ
cos
0
sin
ˆOAsFor nx < ny < nz we found that in principal dielectric axes
−
−
±= −−
−−
−
22
22
1
2,1
sin
zx
yx
nn
nn
δ
SDEs ,,,ˆ
are coplanar
and normal toH
We also found:
DE
DD
n
⋅
⋅
=
0
2 1
ε
const
n
D
DE
y
==⋅ 2
0
2
ε
We found: y
nn =
113. 113
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 6( 12
2
2
2
2
2
=++
zyx n
z
n
y
n
xnx < ny < nz.
Conical Refraction on the Optical Axis (continue – 1(
OAsˆ
Let draw in principal dielectric axes coordinate O,x,y,z,
starting from O, the vectors and . They define the
plane Bπ
T
0=⋅ ET
Since we can find in vectors such thatEBπ
constDE =⋅
and , , and are in the same plane. E OAsˆD
HE
HE
S
×
×
=
→
1
Tπ
Therefore the locus of is the projection of the
circle of from plane to an ellipse in plane
having the Oy axis in common.
E
D Sπ
Since are in the same plane with and
will be on a conical surface with O as a vertex having
and on its surfacesT
OAsˆDHE
HE
S
×
×
=
→
1
→
S1
OAsˆ
114. 114
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 7(
Conical Refraction on the Optical Axis (continue – 2(
Take a biaxial crystal and cut it so that two parallel faces
are perpendicular to the Optical Axis. If a monochromatic
unpolarized light is normal to one of the crystal faces, the
energy will spread out in the plate in a hollow cone, the
cone of internal conical refraction.
When the light exits the crystal the energy and wave
directions coincide, and the light will form a hollow cylinder.
This phenomenon was predicted by William Rowan Hamilton
in 1832 and confirmed experimentally by Lloyd, a year later
(Born & Wolf(.
Because it is no easy to obtain an accurate parallel beam of
monochromatic light on obtained two bright circles
(Born & Wolf(.
William Rowan
Hamilton
(1805-1855(
115. 115
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Index Ellipsoid (continue – 8(
Conical Refraction on the Optical Axis (continue – 3(
Return to Table of Content
116. 116
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
BEs
c
n
DHs
c
n
=×
−=×
ˆ
ˆ
HHIB
ED
µµ
ε
=⋅=
⋅=
( ) E
n
c
D
n
c
Hs
n
c
Bs
n
c
Ess ⋅−=−=×=×=×× εµµµ
2
2
2
2
ˆˆˆˆ
1ˆˆ
0
0
0
ˆˆ 222
=++=⋅
−
−
−
=×⇒
= zyx
xy
xz
yz
z
y
x
sssss
ss
ss
ss
s
s
s
s
s
=
z
y
x
ε
ε
ε
ε
00
00
00
==
0
2
0
2
0
2
22
2
00
00
00
1
ε
ε
ε
ε
ε
ε
ε
µε
µεµ
n
n
n
nn
c
z
y
x
( )
( )
( )
( )
+−
+−
+−
=
+−
+−
+−
=
−
−
−
−
−
−
=××
2
2
2
22
22
22
1
1
1
0
0
0
0
0
0
ˆˆ
zzyzx
zyyyx
zxyxx
yxzyzx
zyzxyx
zxyxzy
xy
xz
yz
xy
xz
yz
sssss
sssss
sssss
ssssss
ssssss
ssssss
ss
ss
ss
ss
ss
ss
ss
Equation of Wave Normal
( ) 0ˆˆ 2
2
=⋅+×× E
n
c
Ess εµ
( ) 0ˆˆ 2
2
1
=+×× −
D
n
c
Dss µε
or
117. 117
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
( ) 0ˆˆ 2
2
=⋅+×× E
n
c
Ess εµ
0
1
1
1
2
0
2
2
0
2
2
0
2
=
+−
+−
+−
z
y
x
z
z
zyzx
zyy
y
yx
zxyxx
x
E
E
E
s
n
ssss
sss
n
ss
sssss
n
ε
ε
ε
ε
ε
ε
The solution is obtained when
−
−+
−
−+
−
−+
−
−
−= 111111111
0
2
0
2
2
0
2
0
2
2
0
2
0
2
2
0
2
0
2
0
2
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
nn
s
nn
s
nn
s
nnn
yx
z
zx
y
yz
x
zyx
+−
+−
+−
=
2
0
2
2
0
2
2
0
2
1
1
1
det0
z
z
zyzx
zyy
y
yx
zxyxx
x
s
n
ssss
sss
n
ss
sssss
n
ε
ε
ε
ε
ε
ε
−−
−−
−+
−+
−
−
+−= 1111111
0
2
22
0
2
22
0
2
2
0
2
2
0
2
0
2
2
0
2
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
n
ss
n
ss
n
s
n
s
nn
s
n
y
zx
z
yx
y
z
z
y
zy
x
x
Equation of Wave Normal (continue – 1(
118. 118
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
0111111111
1
1
1
det
0
2
0
2
2
0
2
0
2
2
0
2
0
2
2
0
2
0
2
0
2
2
0
2
2
0
2
2
0
2
=
−
−+
−
−+
−
−+
−
−
−=
=
+−
+−
+−
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
nn
s
nn
s
nn
s
nnn
s
n
ssss
sss
n
ss
sssss
n
yx
z
zx
y
yz
x
zyx
z
z
zyzx
zyy
y
yx
zxyxx
x
Divide by (assumed nonzero!!(
−
−
−− 111
0
2
0
2
0
2
2
ε
ε
ε
ε
ε
ε
nnn
n zyx
2
0
2
2
0
2
2
0
2
2
1
nn
s
n
s
n
s
z
z
y
y
x
x
=
−
+
−
+
−
ε
ε
ε
ε
ε
ε 222
2
22
2
22
2
1
nnn
s
nn
s
nn
s
z
z
y
y
x
x
=
−
+
−
+
−
0
2
0
2
0
2
,,
ε
ε
ε
ε
ε
ε z
z
y
y
x
x nnn ===
Equation of Wave Normal (continue – 2(
Fresnel equation of wave normal
Fresnel's wave surface, found by Augustin-Jean Fresnel in 1821, is a quartic
surface describing the propagation of light in an optically biaxial crystal
Augustin-Jean Fresnel
(1788 – 1827(
119. 119
SOLO ELECTROMAGNETICS
Planar Waves in an Source-less Anisotropic Electric Media
Equation of Wave Normal (continue – 3(
Fresnel equation of wave normal
02
0
2
0
222
0
2
0
222
0
2
0
222
0
2
0
2
0
=
−
−+
−
−+
−
−+
−
−
− nnsnnnsnnnsnnnn
yx
z
zx
y
yz
x
zyx
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
022
00
42
00
6222
00
42
00
6222
00
42
00
62
000
2
000000
4
000
6
=+
+−++
+−++
+−+
+
++−
+++−
nsnsnsnsnsnsnsnsns
nnn
z
yx
z
yx
zy
zx
y
zx
yx
zy
x
zy
x
zyxzyzxyxzyx
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
( ) ( ) ( ) 0111
000
22
00
2
00
2
00
42
0
2
0
2
0
=+
−+−+−−
++
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε zyx
x
zy
y
zx
z
yx
z
z
y
y
x
x
nsssnsss
0111111111
0
2
0
2
2
0
2
0
2
2
0
2
0
2
2
0
2
0
2
0
2
=
−
−+
−
−+
−
−+
−
−
−
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
ε
nn
s
nn
s
nn
s
nnn
yx
z
zx
y
yz
x
zyx 6
n
This is a quadratic equation of n2
.
For each set sx, sy, sz it yields two solutions for n2
: n1
2
and n2
2
( )snnn ˆ,, 21 ε
=
222
2
22
2
22
2
1
nnn
s
nn
s
nn
s
z
z
y
y
x
x
=
−
+
−
+
−
1
222
=++ zyx sss
Return to Table of Content
Notas del editor
M.V.Klein, T.Furtak,&quot;Optics&quot;, pp.34-35
E. Hecht, A. Zajac,&quot;Optics&quot;,pp.8, pp.225-226
W.Swindell,Ed.,&quot;Polrized Light&quot;, BenchmarkPapers in Optics, V.1, pg.10 and 25
M.V.Klein, T.Furtak,&quot;Optics&quot;, pp.34-35
E. Hecht, A. Zajac,&quot;Optics&quot;,pp.8, pp.225-226
M. Born, E. Wolf,&quot;Principles of Optics&quot;, pp. xxiii
M.V. Klein, T. Furtak,&quot;Optics&quot;, pp.35
Maffett, &quot;Topics for a Statistical Description of Radar Cross Section&quot;, pp.47
Maffett, &quot;Topics of Statistical Description of Radar Cross Section&quot;, 1988, pp.25-27 and 287-289
Maffett, &quot;Topics of Statistical Description of Radar Cross Section&quot;, 1988, pp.25-27 and 287-289
Maffett, &quot;Topics of Statistical Description of Radar Cross Section&quot;, 1988, pp.25-27 and 287-289
A. Yariv, P. Yeh,&quot;Optical Waves in Crystals&quot;, John Wiley & Sons, 1984, pp.79-82
A. Maffett,&quot;Topics of Statistical Description of Radar Cross Sections&quot;, John Wiley & Sons, 1988, pp.314
G.R. Fowles,&quot;Introduction to Modern Optics&quot;, 2nd Ed., Dover, p. 176
Yariv & Yeh,&quot;Optical Waves in Crystals&quot;, John Wiley & Sons, 1984, p.85
Yariv & Yeh, &quot;Optical Waves in Crystals&quot;,John Willey & Sons, 1984, p.85
G.R. Fowles, &quot;Introduction to Modern Optics&quot;, 2nd Ed., Dover, 1975, p.176
A. Yariv, P. Yeh &quot;Optical Waves in Crystals&quot;,1984, John Wiley & Sons, p.83
A. Mermin, &quot;Solid State Physics&quot;,Holt, Reinhart and Winston, 1976, p.116
http://www.tulane.edu/~sanelson/eens211/32crystalclass.htm
A. Yariv, P. Yeh &quot;Optical Waves in Crystals&quot;,1984, John Wiley & Sons, p.83
A. Mermin, &quot;Solid State Physics&quot;,Holt, Reinhart and Winston, 1976, p.116
http://www.tulane.edu/~sanelson/eens211/32crystalclass.htm
A. Yariv, P. Yeh &quot;Optical Waves in Crystals&quot;,1984, John Wiley & Sons, p.83
A. Mermin, &quot;Solid State Physics&quot;,Holt, Reinhart and Winston, 1976, p.116
http://www.tulane.edu/~sanelson/eens211/32crystalclass.htm
A. Yariv, P. Yeh,&quot;Optical Waves in Crystals&quot;, John Wiley & Sons, 1984, pp.79-82
A. Maffett,&quot;Topics of Statistical Description of Radar Cross Sections&quot;, John Wiley & Sons, 1988, pp.314
G.R. Fowles,&quot;Introduction to Modern Optics&quot;, Dover, 1975, pp.178-180
Born & Wolf, &quot;Principle of Optics&quot;, 6th Ed., pp.686-690
M.V. Klein,&quot;Optics&quot;, 1970, pp.609
Born & Wolf, &quot;Principle of Optics&quot;, 6th Ed., pp.686-690
M.V. Klein,&quot;Optics&quot;, 1970, pp.609