Commit 46365e90 authored by Claude Meny's avatar Claude Meny

Update textbook.fr.md

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...@@ -231,8 +231,8 @@ conductor. For the perfect conductor, as *σ* , its penetration depth ...@@ -231,8 +231,8 @@ conductor. For the perfect conductor, as *σ* , its penetration depth
transmission can occur, the wave is totally reflected. The incident transmission can occur, the wave is totally reflected. The incident
and reflected waves are: and reflected waves are:
![]() ![](electromag-in-media-reflexion-transmission-fig-33a.jpg)
![]() ![](electromag-in-media-reflexion-transmission-fig-33b.jpg)
$`\overrightarrow{E}`$*~r~* $`\overrightarrow{B}`$*~r~* $`\overrightarrow{E}`$*~r~* $`\overrightarrow{B}`$*~r~*
medium 2 perfect conductor medium 2 perfect conductor
...@@ -286,8 +286,8 @@ time-averaged values is indeed *\<* $`\overrightarrow{S}`$*~tot~ \>~t~*= 0. ...@@ -286,8 +286,8 @@ time-averaged values is indeed *\<* $`\overrightarrow{S}`$*~tot~ \>~t~*= 0.
Due to the discontinuity of the magnetic field, a surface current Due to the discontinuity of the magnetic field, a surface current
density must density must
![]() ![](electromag-in-media-reflexion-transmission-fig-34a.jpg)
![]() ![](electromag-in-media-reflexion-transmission-fig-34b.jpg)
_Figure 3.4: Left: The incident, reflected and resulting wave at a_ _Figure 3.4: Left: The incident, reflected and resulting wave at a_
_particular time. Right: The superposition of several resulting waves_ _particular time. Right: The superposition of several resulting waves_
_at different times. See the video of the simulation on the_ _at different times. See the video of the simulation on the_
...@@ -305,8 +305,8 @@ $`\overrightarrow{j}`$*~s~* = 0). The incident ware is given by ...@@ -305,8 +305,8 @@ $`\overrightarrow{j}`$*~s~* = 0). The incident ware is given by
@@@@@@@@ $`\quad (equ. 3.28)`$ @@@@@@@@ $`\quad (equ. 3.28)`$
![]() ![](electromag-in-media-reflexion-transmission-fig-35a.jpg)
![]() ![](electromag-in-media-reflexion-transmission-fig-35b.jpg)
_Figure 3.5: Left: Normal incidence at the boundary between twp perfect_ _Figure 3.5: Left: Normal incidence at the boundary between twp perfect_
_dielectrics. Right the total fields in medium 1 at a few different_ _dielectrics. Right the total fields in medium 1 at a few different_
_times showing a partial standing wave. The minimum amplitude of_ _times showing a partial standing wave. The minimum amplitude of_
...@@ -345,16 +345,20 @@ and ...@@ -345,16 +345,20 @@ and
@@@@@@@@@ @@@@@@@@@
#### chap2 Reflection and transmission at oblique incidence <br>
------------------
#### 3.3 - Reflection and transmission at oblique incidence
We now turn to the more general case of an oblique incidence at an We now turn to the more general case of an oblique incidence at an
arbitrary angle *θ~i~*. Before that we will need a few definitions and arbitrary angle *θ~i~*. Before that we will need a few definitions and
considerations. considerations.
![](media/image182.png) ![](electromag-in-media-reflexion-transmission-fig-36.jpg)
_Figure 3.6: Plane of incidence, *s* and *p* polarisations._ _Figure 3.6: Plane of incidence, *s* and *p* polarisations._
##### chap5 Plane of incidence ##### Plane of incidence
We first define the **plane of incidence** as the plane the contains We first define the **plane of incidence** as the plane the contains
the incidence wavevector and the normal to the interface separating the incidence wavevector and the normal to the interface separating
...@@ -376,7 +380,7 @@ Two special cases arise: ...@@ -376,7 +380,7 @@ Two special cases arise:
Any other polarisation state can be decomposed into the sum of a TM Any other polarisation state can be decomposed into the sum of a TM
and TE wave. and TE wave.
##### chap5 Laws of reflection and refraction ##### Laws of reflection and refraction
We will derive here the laws of reflection and refraction by making We will derive here the laws of reflection and refraction by making
use of the boundary conditions which are independent on the use of the boundary conditions which are independent on the
...@@ -389,7 +393,7 @@ demonstrate it here. Let's consider the the general situation as of an ...@@ -389,7 +393,7 @@ demonstrate it here. Let's consider the the general situation as of an
inci- dent, reflected and refracted wave as depicted in figure inci- dent, reflected and refracted wave as depicted in figure
[3.7.]. The three plane [3.7.]. The three plane
![]() ![](electromag-in-media-reflexion-transmission-fig-37.jpg)
_Figure 3.7: General case of reflection and refraction_ _Figure 3.7: General case of reflection and refraction_
monochromatic wave are: monochromatic wave are:
...@@ -431,6 +435,9 @@ As **r***~s~* belongs to the interface, (**k***~i~* **k***~r~*) is ...@@ -431,6 +435,9 @@ As **r***~s~* belongs to the interface, (**k***~i~* **k***~r~*) is
normal to it. This means that the vectors **k***~i~*, **k***~r~* and normal to it. This means that the vectors **k***~i~*, **k***~r~* and
the normal belong to the same plane, i.e. the plane of incidence. the normal belong to the same plane, i.e. the plane of incidence.
!! *First law of reflexion*
!! ....
iii. Equation [3.38](#_bookmark65) can be recast as iii. Equation [3.38](#_bookmark65) can be recast as
@@@@@@@@ $`\quad (equ. 3.40)`$ @@@@@@@@ $`\quad (equ. 3.40)`$
...@@ -447,11 +454,20 @@ c. @@@@@@@ ...@@ -447,11 +454,20 @@ c. @@@@@@@
From the first two relations we get *θ~i~* = *θ~r~* as \|*k~i~*\| = From the first two relations we get *θ~i~* = *θ~r~* as \|*k~i~*\| =
\|*k~r~*\|. \|*k~r~*\|.
!! *Second law of reflexion*
!! ....
From the first and the third we get \|*k~i~*\| sin *θ~i~* = \|*k~t~*\| From the first and the third we get \|*k~i~*\| sin *θ~i~* = \|*k~t~*\|
sin *θ~t~* or sin *θ~t~* or
#### chap2 Fresnel's laws & Brewster's angle !! *Snell law*
!! ....
<br>
--------------
#### Fresnel's laws & Brewster's angle
From the previous section we can write the incident, reflected and From the previous section we can write the incident, reflected and
transmitted waves as: transmitted waves as:
...@@ -466,10 +482,11 @@ Likewise for a TM incident wave. ...@@ -466,10 +482,11 @@ Likewise for a TM incident wave.
##### chap3 TE Wave TM Wave ##### chap3 TE Wave TM Wave
![](media/image184.png) ![](media/image187.png) ![](electromag-in-media-reflexion-transmission-fig-38a.jpg)
![](electromag-in-media-reflexion-transmission-fig-38b.jpg)
_Figure 3.8: Configuration for a TE and TM incidence._ _Figure 3.8: Configuration for a TE and TM incidence._
__**chap5 TE Wave**__ __TE Wave__
$`\overrightarrow{E}`$ is tangential and $`\overrightarrow{B}`$ is contained in the plane of incidence. $`\overrightarrow{E}`$ is tangential and $`\overrightarrow{B}`$ is contained in the plane of incidence.
From figure [3.8](#_bookmark67) we can write using the two tangential From figure [3.8](#_bookmark67) we can write using the two tangential
...@@ -487,7 +504,10 @@ which by solving the previous equations can be evaluated to: ...@@ -487,7 +504,10 @@ which by solving the previous equations can be evaluated to:
@@@@@@@@ $`\quad (equ. 3.43)`$ @@@@@@@@ $`\quad (equ. 3.43)`$
__**chap5 TM Wave**__ ! *Remarks*
! ....
__TM Wave__
$`\overrightarrow{E}`$ is s contained in the plane of incidence and $`\overrightarrow{B}`$ is $`\overrightarrow{E}`$ is s contained in the plane of incidence and $`\overrightarrow{B}`$ is
transverse. From figure [3.8](#_bookmark67) we can write using the two transverse. From figure [3.8](#_bookmark67) we can write using the two
...@@ -501,7 +521,8 @@ coefficients for a TM (/I or *p*) wave as: ...@@ -501,7 +521,8 @@ coefficients for a TM (/I or *p*) wave as:
@@@@@@@@ $`\quad (equ. 3.44)`$ @@@@@@@@ $`\quad (equ. 3.44)`$
chap4 Brewster's angle
##### Brewster's angle
Let's make a few considerations on the consequences of the Fresnel Let's make a few considerations on the consequences of the Fresnel
relations by plotting the reflection coefficients for *s* and *p* relations by plotting the reflection coefficients for *s* and *p*
...@@ -514,7 +535,8 @@ a. If @@@@@@@ ...@@ -514,7 +535,8 @@ a. If @@@@@@@
b. If @@@@@@@@ b. If @@@@@@@@
chap5 Case a)
##### Case a)
In this case, we consider the range 0 *θ*~1~ *π/*2 for the incident In this case, we consider the range 0 *θ*~1~ *π/*2 for the incident
angle *θ*~1~. Correspondingly, the refraction angle *θ*~2~ will vary angle *θ*~1~. Correspondingly, the refraction angle *θ*~2~ will vary
...@@ -522,12 +544,16 @@ in the range 0 *θ*~2~ *θ*2*max*. Using Snell we have: ...@@ -522,12 +544,16 @@ in the range 0 *θ*~2~ *θ*2*max*. Using Snell we have:
@@@@@@@@@@@ @@@@@@@@@@@
![]() ![](electromag-in-media-reflexion-transmission-fig-39a.jpg)
![](electromag-in-media-reflexion-transmission-fig-39b.jpg)
_Figure 3.9: The snell law for *n*~1~ *\< n*~2~ and *n*~1~ *\n*~2~._ _Figure 3.9: The snell law for *n*~1~ *\< n*~2~ and *n*~1~ *\n*~2~._
Angle of incidence (deg) Angle of incidence (deg)
![](electromag-in-media-reflexion-transmission-fig-310a.jpg)
![](electromag-in-media-reflexion-transmission-fig-310b.jpg)
![](electromag-in-media-reflexion-transmission-fig-310a.jpg)
![](electromag-in-media-reflexion-transmission-fig-310b.jpg)
_Figure 3.10: Plot of the reflection_ _Figure 3.10: Plot of the reflection_
_coefficients (*r*~⊥~ and *r*I/) and the correspond- ing reflectivities_ _coefficients (*r*~⊥~ and *r*I/) and the correspond- ing reflectivities_
_(*R*~⊥~ and *R*I/) for case a (top) and case b (bottom)._ _(*R*~⊥~ and *R*I/) for case a (top) and case b (bottom)._
...@@ -555,14 +581,15 @@ suggests different applications: ...@@ -555,14 +581,15 @@ suggests different applications:
wave thought an interface using a proper polarisation and wave thought an interface using a proper polarisation and
incidence angle. incidence angle.
![](media/image191.png) ![]()
_Figure 3.11: An illustration of the_ _Figure 3.11: An illustration of the_
_polarisation of light that is incident on an interface at Brewster's_ _polarisation of light that is incident on an interface at Brewster's_
_angle._ _angle._
_[https://en.wikipedia.org/wiki/Brewster'](https://en.wikipedia.org/wiki/Brewster%27s_angle)_ _[https://en.wikipedia.org/wiki/Brewster'](https://en.wikipedia.org/wiki/Brewster%27s_angle)_
_[s_angle](https://en.wikipedia.org/wiki/Brewster%27s_angle)_ _[s_angle](https://en.wikipedia.org/wiki/Brewster%27s_angle)_
chap5 Case b)
##### Case b)
In this case, total reflections will occur for angles *θ*~1~ In this case, total reflections will occur for angles *θ*~1~
*θ*1*lim*. The considera- tions on the Brewster's angle stated above *θ*1*lim*. The considera- tions on the Brewster's angle stated above
...@@ -595,7 +622,7 @@ the transmitted and reflected beams are perpendicular, see figure ...@@ -595,7 +622,7 @@ the transmitted and reflected beams are perpendicular, see figure
to show that *θ~B~ \< θ*1*lim*, i.e. the Brewster's angle is to show that *θ~B~ \< θ*1*lim*, i.e. the Brewster's angle is
always smaller than the limit angle for total reflection. always smaller than the limit angle for total reflection.
chap4 Total internal reflection ##### Total internal reflection
Let's consider the oblique incidence shown in figure Let's consider the oblique incidence shown in figure
[3.8.](#_bookmark67) The transmitted field is given by [3.8.](#_bookmark67) The transmitted field is given by
...@@ -641,7 +668,11 @@ but also ...@@ -641,7 +668,11 @@ but also
i.e. the reflected wave is totally reflected with a phase shift. i.e. the reflected wave is totally reflected with a phase shift.
chap2 Oblique incidence onto a perfect conductor <br>
----------------
#### Oblique incidence onto a perfect conductor
We consider now a linearly polarised plane wave travelling in a We consider now a linearly polarised plane wave travelling in a
perfect dielec- tric making an oblique incidence onto a perfect perfect dielec- tric making an oblique incidence onto a perfect
...@@ -654,7 +685,9 @@ separately. As before, being the second medium a perfect conductor, no ...@@ -654,7 +685,9 @@ separately. As before, being the second medium a perfect conductor, no
electromagnetic fields can exists in it. We will deal only with the electromagnetic fields can exists in it. We will deal only with the
incident and reflected fields. incident and reflected fields.
chap5 TE Wave Incident fields ##### TE Wave
##### Incident fields
Considering the situation depicted in figure [3.13,](#_bookmark74) the Considering the situation depicted in figure [3.13,](#_bookmark74) the
incident wavevector is given by: incident wavevector is given by:
......
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