Optics B/C

Skink
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Re: Optics B/C

Postby Skink » April 4th, 2017, 6:06 pm

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.

kenniky
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Re: Optics B/C

Postby kenniky » April 7th, 2017, 12:29 pm

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

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
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Re: Optics B/C

Postby jkang » April 7th, 2017, 3:35 pm

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.
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kenniky
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Re: Optics B/C

Postby kenniky » April 7th, 2017, 3:52 pm

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

Also, @jkang, I think the first polarization would be and the second would be
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Re: Optics B/C

Postby jkang » April 7th, 2017, 3:55 pm

Also, @jkang, I think the first polarization would be and the second would be
Oops, you're right about that.
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Re: Optics B/C

Postby ChingCL » April 10th, 2017, 10:28 pm

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

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Re: Optics B/C

Postby kenniky » April 11th, 2017, 6:26 am

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
How much are you willing to sell it for ;)

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

Postby ChingCL » April 11th, 2017, 10:30 pm

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
How much are you willing to sell it for ;)

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
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
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Re: Optics B/C

Postby kenniky » April 12th, 2017, 6:07 am

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
How much are you willing to sell it for ;)

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
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.
Oh, wow, that's great, thank you! I can 3D print it myself, don't worry about it (:
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Re: Optics B/C

Postby Avogadro » April 16th, 2017, 6:19 pm

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


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