Browse Source

suite

keep-around/ecadacf81d76dfedf1ca3e2d0db35111f186bee4
Claude Meny 6 years ago
parent
commit
ecadacf81d
  1. 70
      01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md

70
01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md

@ -62,7 +62,7 @@ refracting interface corresponds to two different plane refracting surfaces :<br
!!!! \- refracting index of the medium of the emergent light : $n_{eme} = n_{water} = 1.33$.
!!!!
####
#### Difference in terminology between Spanish, French and English
!!!! *BE CAREFUL* :<br>
!!!! In the same way as we use in English the single word "mirror" to qualify a "reflecting surface", in French is use the single word "dioptre" to qualify a "refracting surface".
@ -119,7 +119,7 @@ $`sin(\alpha) \approx tan (\alpha) \approx \alpha`$, and $`cos(\alpha) \approx
We call **thin spherical refracting surface** a spherical refracting surface *used in the Gauss conditions*.
### How is modeled in paraxial optics ?
### How is modeled a spherical refracting surface in paraxial optics ?
#### Characterization of a spherical refracting surface
@ -132,72 +132,30 @@ which defines $`\overline{SC}`$ : algebraic distance between vertex S and center
\- **$`n-{eme} : refractive index of the medium of the emergent light**.
* 1 arrow : indicates the *direction of light propagation*
#### Analytical study
### Spherical refracting surface modeling.
#### Description
*
![](dioptre-1.gif)
with :
* arrow : indicates direction of light propagation.
* $`n_{ini}`$ : refractive index of the initial medium.
* $`n_{fin}`$ : refractive index of the final medium.
* $`\overline{SC}`$ : algebraic distance between vertex S and center C of curvature on optical axis.
!!!! *BE CAREFUL* :<br>
!!!! In the same way as we use in English the single word "mirror" to qualify a "reflecting surface", in French is use the single word "dioptre" to qualify a "refracting surface".
!!!! The term "dioptre" in English is a unit of mesure of the vergence of an optical system. In French, the same unit of measure is named "dioptrie".
!!!! So keep in mind the following scheme :
!!!!
!!!! refracting surface : *EN : refracting surface* , *ES : superficie refractiva* , *FR : dioptre*.<br>
!!!! _A crystal ball forms a spherical refracting surface : un "dioptre sphérique" in French._
!!!!
!!!! unit of measure : *EN : dioptre* , *ES : dioptría* , *FR : dioptrie*.<br>
!!!! _My corrective lens for both eyes are 4 dioptres : "4 dioptries" in French._
#### Spherical refracting surface.
#### Analytical study
A **spherical refracting surface** in analytical paraxial optics is defined by *three quantities* :
* **$`n_{ini}`$** : *refractive index of the initial medium* (the medium on the side on the incident light).
* **$`n_{fin}`$** : *refractive index of the final medium* (the medium on the side on the emerging light, after crossing the refracting surface).
* **$`\overline{SC}`$** : the *algebraic distance between the __vertex S__* (sometimes called "pole", is the centre of the aperture) *and the __center of curvature C__* of the refracting surface.
! *USEFUL* : The whole analytic study below also applies to a plane refracting surface. We just need to remark that a plane surface is a spherical surface whose radius of curvature tends towards infinity.
##### Spherical refracting surface equation
**spherical refracting surface equation** = **"conjuction equation" for a spherical refracting surface**
**$`\dfrac{n_{fin}}{\overline{SA_{ima}}}-\dfrac{n_{ini}}{\overline{SA_{obj}}}=\dfrac{n_{fin}-n_{ini}}{\overline{SC}}`$**
#### Analytical study
##### Transverse magnification expression
2. I use the **"transverse magnification equation" for a spherical refracting surface**, to calculate the *__algebraic value__ of the transverse magnification* **$`\overline{M_T}`$**, then to derive the *__algebraic length__* **$`\overline{A_{ima}B_{ima}}`$** of the segment $`[A_{ima}B_{ima}]`$, that is the algebraic distance of the point image $`B_{ima}`$ from its orthogonal projection $`A_{ima}`$ on the optical axis.
* **Thin spherical refracting surface equation** = **conjuction equation** for a spherical refracting surface<br><br>
**$`\dfrac{n_{eme}}{\overline{SA_{ima}}}-\dfrac{n_{inc}}{\overline{SA_{obj}}}=\dfrac{n_{eme}-n_{inc}}{\overline{SC}}`$**&nbsp;&nbsp; (equ.1)
By *definition :* **$`\overline{M_T}=\dfrac{\overline{A_{ima}B_{ima}}}{\overline{A_{obj}B_{obj}}}`$**.
Its *expression for spherical refracting surface :* **$`\overline{M_T}=\dfrac{n_{ini}\cdot\overline{SA_{ima}}}{n_{fin}\cdot\overline{SA_{obj}}}`$**.
* **Transverse magnification expression**<br><br>
**$`\overline{M_T}=\dfrac{n_{inc}\cdot\overline{SA_{ima}}}{n_{eme}\cdot\overline{SA_{obj}}}`$**&nbsp;&nbsp; (equ.2)
I know $`\overline{SA_{obj}}$, $n_{ini}$ and $n_{fin}$, I have previously calculated $`\overline{SA_{ima}}$, so I can calculate $`\overline{M_T}`$ and deduced $`\overline{A_{ima}B_{ima}}`$
You know $`\overline{SA_{obj}}$, $n_{inc}$ and $n_{eme}`$, you have previously calculated $`\overline{SA_{ima}}`$, so you can calculate $`\overline{M_T}`$ and deduced $`\overline{A_{ima}B_{ima}}`$.
! *USEFUL* : The conjuction equation and the transverse magnification equation for a plane refracting surface are obtained by rewriting these equations for a spherical refracting surface in the limit when $`|\overline{SC}|\longrightarrow\infty`$.<br> Then we get *for a plane refracting surface :*
!
! * *conjuction equation :*&nbsp;&nbsp; $`\dfrac{n_{fin}}{\overline{SA_{ima}}}-\dfrac{n_{ini}}{\overline{SA_{obj}}}=0`$.
!
! * *transverse magnification equation :*&nbsp;&nbsp; $`\dfrac{n_{ini}\cdot\overline{SA_{ima}}}{n_{fin}\cdot\overline{SA_{obj}}}`$ &nbsp;&nbsp; (unchanged).
! * *conjuction equation :*&nbsp;&nbsp; $`\dfrac{n_{fin}}{\overline{SA_{ima}}}-\dfrac{n_{ini}}{\overline{SA_{obj}}}=0`$ &nbsp;&nbsp; (equ.3)
!
! This generalizes and completes the knowledge you get about plane refracting surfaces seen in your pedagogical paths in plain and hills.
! * *transverse magnification equation :*&nbsp;&nbsp; $`\dfrac{n_{ini}\cdot\overline{SA_{ima}}}{n_{fin}\cdot\overline{SA_{obj}}}`$
&nbsp;&nbsp; (equ.2, unchanged)<br><br>
but (equ.3) gives $`\dfrac{\overline{SA_{ima}}}{\overline{SA_{obj}}}=\dfrac{n_{inc}}{n_{eme}}`$.<br>
Copy this result into (equ.2) leads to $`\overline{M_T}=+1`$.
#### Graphical study
Loading…
Cancel
Save