Optics B/C
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Re: Optics B/C
Great, that's the same take I got. See, my State more than encourages hands-on work at the State level, so my Optics team should probably drag out the lenses just in case.
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Re: Optics B/C
Something I'm confused on -
http://hyperphysics.phy-astr.gsu.edu/hb ... ar.html#c3
It says that reflectance for waves parallel to the plane of incidence is![](http://latex.codecogs.com/png.latex?\frac{tan^2(\alpha - \beta)}{tan^2(\alpha + \beta)})
if
and
add to 90, (which is the Brewster angle condition), shouldn't it be zero? but obviously it isn't
is it wrong?
On wikipedia it states that the actual equations are somewhat different...
https://en.wikipedia.org/wiki/Fresnel_equations
http://hyperphysics.phy-astr.gsu.edu/hb ... ar.html#c3
It says that reflectance for waves parallel to the plane of incidence is
if
is it wrong?
On wikipedia it states that the actual equations are somewhat different...
https://en.wikipedia.org/wiki/Fresnel_equations
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Re: Optics B/C
I actually just went over this in my EM class. Due to the way Maxwell's equations and boundary conditions at the interface work out, there'll be two different polarizations of light with separate equations - one where the magnetic component of the wave is parallel to the interface, and one where the electric component is parallel.
For the first polarization, the Fresnel relations can be derived as
, where
and
(note that the notation I'm using is different than hyperphysics').
For the second polarization, the Fresnel relations can be derived as
.
If you plot these out, you can find that for the polarization where the magnetic component is parallel to the interface, there is no reflection at the Brewster angle (
). For the polarization where the electric component is parallel, there is no such thing.
Looking at hyperphysics, it seems the first polarization is
(s-polarized), and the second is
(p-polarized). From there, you can try messing around with trig identities and algebra and see if you can derive hyperphysics' equation. If not, I'd go with what I (and seemingly Wikipedia) provided.
For the first polarization, the Fresnel relations can be derived as
For the second polarization, the Fresnel relations can be derived as
If you plot these out, you can find that for the polarization where the magnetic component is parallel to the interface, there is no reflection at the Brewster angle (
Looking at hyperphysics, it seems the first polarization is
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Liberal Arts and Science Academy '15
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Re: Optics B/C
Oh, I figured out what was going on.
and
add to 90 degrees, so the bottom of the
goes to infinity which causes the whole thing to go to zero, but that doesn't happen for ![](http://latex.codecogs.com/png.latex?r_\perp)
Also, @jkang, I think the first polarization would be
and the second would be ![](http://latex.codecogs.com/png.latex?r_\perp)
Also, @jkang, I think the first polarization would be
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Re: Optics B/C
Oops, you're right about that.kenniky wrote:Also, @jkang, I think the first polarization would beand the second would be
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Re: Optics B/C
I have made a Laser Shoot Setup for my Science Olympiad students to practice positioning mirrors for a laser beam to hit a target. The setup was built using the instructions on the SO website except the following: The laser was mounted on a 3D printed fixture (white part on the LSS picture) with three adjustable screws to align the laser beam to the center of the back wall. Batteries can be changed without disturbing the laser alignment. The laser is protected from accidental bump.
A link to the pictures
https://drive.google.com/drive/folders/ ... kx5bHJRZzQ
A link to the pictures
https://drive.google.com/drive/folders/ ... kx5bHJRZzQ
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Re: Optics B/C
How much are you willing to sell it forChingCL wrote:I have made a Laser Shoot Setup for my Science Olympiad students to practice positioning mirrors for a laser beam to hit a target. The setup was built using the instructions on the SO website except the following: The laser was mounted on a 3D printed fixture (white part on the LSS picture) with three adjustable screws to align the laser beam to the center of the back wall. Batteries can be changed without disturbing the laser alignment. The laser is protected from accidental bump.
A link to the pictures
https://drive.google.com/drive/folders/ ... kx5bHJRZzQ
![Wink ;)](./images/smilies/icon_e_wink.gif)
Haha just kidding, looks amazing though! I'd love to have a similar one for practice, or even just to see it used in competition
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Re: Optics B/C
Kenny, Thanks for sharing videos and files! If you plan to build an LSS, I offer one 3D printed Laser Mount device sent to you free of charge. Additional files are uploaded.kenniky wrote:How much are you willing to sell it forChingCL wrote:I have made a Laser Shoot Setup for my Science Olympiad students to practice positioning mirrors for a laser beam to hit a target. The setup was built using the instructions on the SO website except the following: The laser was mounted on a 3D printed fixture (white part on the LSS picture) with three adjustable screws to align the laser beam to the center of the back wall. Batteries can be changed without disturbing the laser alignment. The laser is protected from accidental bump.
A link to the pictures
https://drive.google.com/drive/folders/ ... kx5bHJRZzQ
Haha just kidding, looks amazing though! I'd love to have a similar one for practice, or even just to see it used in competition
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Re: Optics B/C
Oh, wow, that's great, thank you! I can 3D print it myself, don't worry about it (:ChingCL wrote:Kenny, Thanks for sharing videos and files! If you plan to build an LSS, I offer one 3D printed Laser Mount device sent to you free of charge. Additional files are uploaded.kenniky wrote:How much are you willing to sell it forChingCL wrote:I have made a Laser Shoot Setup for my Science Olympiad students to practice positioning mirrors for a laser beam to hit a target. The setup was built using the instructions on the SO website except the following: The laser was mounted on a 3D printed fixture (white part on the LSS picture) with three adjustable screws to align the laser beam to the center of the back wall. Batteries can be changed without disturbing the laser alignment. The laser is protected from accidental bump.
A link to the pictures
https://drive.google.com/drive/folders/ ... kx5bHJRZzQ
Haha just kidding, looks amazing though! I'd love to have a similar one for practice, or even just to see it used in competition
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Re: Optics B/C
Actually, if you're willing to give out the schematics, I think a lot of us around here could do with an "idiot-proof" design (having messed up my LS in practice quite a few times myself).
Lower Merion 2017
Subtitled: Revenge of the Non-Harriton
Placement Record:
Code: Islip | Conestoga | Tiger | Regionals | States
Out of: 61 | 42 | 36 | 37 | 36
Chemistry Lab: 9 | - | - | 4 | 4
Astronomy: 14 | - | 5 | 10 | 3
Material Science: 12 | 19 | 9 | 5 | 9
Optics: 14 | 7 | 3 | 4 | 2
Subtitled: Revenge of the Non-Harriton
Placement Record:
Code: Islip | Conestoga | Tiger | Regionals | States
Out of: 61 | 42 | 36 | 37 | 36
Chemistry Lab: 9 | - | - | 4 | 4
Astronomy: 14 | - | 5 | 10 | 3
Material Science: 12 | 19 | 9 | 5 | 9
Optics: 14 | 7 | 3 | 4 | 2