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

Update textbook.fr.md

parent 5cb2178a
Pipeline #14816 canceled with stage
......@@ -231,8 +231,8 @@ conductor. For the perfect conductor, as *σ* , its penetration depth
transmission can occur, the wave is totally reflected. The incident
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~*
medium 2 perfect conductor
......@@ -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
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_
_particular time. Right: The superposition of several resulting waves_
_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
@@@@@@@@ $`\quad (equ. 3.28)`$
![]()
![]()
![](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_
_dielectrics. Right the total fields in medium 1 at a few different_
_times showing a partial standing wave. The minimum amplitude of_
......@@ -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
arbitrary angle *θ~i~*. Before that we will need a few definitions and
considerations.
![](media/image182.png)
![](electromag-in-media-reflexion-transmission-fig-36.jpg)
_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
the incidence wavevector and the normal to the interface separating
......@@ -376,7 +380,7 @@ Two special cases arise:
Any other polarisation state can be decomposed into the sum of a TM
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
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
inci- dent, reflected and refracted wave as depicted in figure
[3.7.]. The three plane
![]()
![](electromag-in-media-reflexion-transmission-fig-37.jpg)
_Figure 3.7: General case of reflection and refraction_
monochromatic wave are:
......@@ -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
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
@@@@@@@@ $`\quad (equ. 3.40)`$
......@@ -447,11 +454,20 @@ c. @@@@@@@
From the first two relations we get *θ~i~* = *θ~r~* as \|*k~i~*\| =
\|*k~r~*\|.
!! *Second law of reflexion*
!! ....
From the first and the third we get \|*k~i~*\| sin *θ~i~* = \|*k~t~*\|
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
transmitted waves as:
......@@ -466,10 +482,11 @@ Likewise for a TM incident 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._
__**chap5 TE Wave**__
__TE Wave__
$`\overrightarrow{E}`$ is tangential and $`\overrightarrow{B}`$ is contained in the plane of incidence.
From figure [3.8](#_bookmark67) we can write using the two tangential
......@@ -487,7 +504,10 @@ which by solving the previous equations can be evaluated to:
@@@@@@@@ $`\quad (equ. 3.43)`$
__**chap5 TM Wave**__
! *Remarks*
! ....
__TM Wave__
$`\overrightarrow{E}`$ is s contained in the plane of incidence and $`\overrightarrow{B}`$ is
transverse. From figure [3.8](#_bookmark67) we can write using the two
......@@ -501,7 +521,8 @@ coefficients for a TM (/I or *p*) wave as:
@@@@@@@@ $`\quad (equ. 3.44)`$
chap4 Brewster's angle
##### Brewster's angle
Let's make a few considerations on the consequences of the Fresnel
relations by plotting the reflection coefficients for *s* and *p*
......@@ -514,7 +535,8 @@ a. If @@@@@@@
b. If @@@@@@@@
chap5 Case a)
##### Case a)
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
......@@ -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~._
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_
_coefficients (*r*~⊥~ and *r*I/) and the correspond- ing reflectivities_
_(*R*~⊥~ and *R*I/) for case a (top) and case b (bottom)._
......@@ -555,14 +581,15 @@ suggests different applications:
wave thought an interface using a proper polarisation and
incidence angle.
![](media/image191.png)
![]()
_Figure 3.11: An illustration of the_
_polarisation of light that is incident on an interface at Brewster's_
_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)_
chap5 Case b)
##### Case b)
In this case, total reflections will occur for angles *θ*~1~
*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
to show that *θ~B~ \< θ*1*lim*, i.e. the Brewster's angle is
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
[3.8.](#_bookmark67) The transmitted field is given by
......@@ -641,7 +668,11 @@ but also
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
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
electromagnetic fields can exists in it. We will deal only with the
incident and reflected fields.
chap5 TE Wave Incident fields
##### TE Wave
##### Incident fields
Considering the situation depicted in figure [3.13,](#_bookmark74) the
incident wavevector is given by:
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment