Thick Lens

[Fu-Kwun Hwang]

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There are 7 translations, select to view translated versionBahasa Indonesia - Indonesian(by choirulfasih: 20)English(by samaksh13: 26)Română - Romanian(by extr3m3: 20)English(by awzh08@xtreme4.pipex.net: 23)Português - Brazilian portuguese(by hatuey: 21)Română - Romanian(by lucumon20010: 17)English(by JoeBova: 8)
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or

When a beam of light meet the boundary between two different media,

some light is reflected back to the same media

(law of reflection)

some light is refracted to a different media

( law of refraction).

The same laws applied when light wave impinging the surface of a lens.
This java applet let you play with a thick lens.


How to play:

You can enter the index of refraction of the lens into the Text Field.

The gray ellipse area represents the thick lens.
You can click the left mouse button within one of four cyan circle around the lens

and drag the mouse button to change the shape of the lens.

You can click the circle at the center of the ellipse and drag the mouse left/right to move the lens horizontally.
Light beam entering from the left of the screen.

You can click at the beam and drag it up/down. Hit Reset button for default conditions.

Approximate indices of refraction of various substance

Air	1.00029
ice	1.31
water	1.333
Ethyl alcohol	1.36
Fused quartz SiO2	1.4584
glass	1.5 - 1.6
diamond	2.417
Futile TiO2	2.907
Gallium phosphide	3.50

http://www.youtube.com/watch?v=EXmaY2txEBo

Registed user can get files related to this applet for offline access.
Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
If java program did not show up, please download and install latest Java RUN TIME

There are 7 translations, select to view translated versionBahasa Indonesia - Indonesian(by choirulfasih: 20)English(by samaksh13: 26)Română - Romanian(by extr3m3: 20)English(by awzh08@xtreme4.pipex.net: 23)Português - Brazilian portuguese(by hatuey: 21)Română - Romanian(by lucumon20010: 17)English(by JoeBova: 8)
Higher number at the end means more translation been done.

or

[PELADO]

OK 
TKS FOR ALL YOU ARE A GENIUS

[Wieslaw]

It is really nice, however I would like to suggest making another similar applet, a little more complicated. It could show the rays in a human eye. There just should be some procedures used here repeated more times.

[leeyiren]

prof, am i right to say that this simulation is to show us that the thicker the lens, the shorter the focal length?

[leeyiren]

can anyone briefly tell me what is the equation in the simulation?

[Fu-Kwun Hwang]

Refraction obey Snell's Law

[leeyiren]

Refraction obey Snell's Law

what i mean is the equation "x^2/n+y^2/n=1"

i dun see the snell's law in it?

[Fu-Kwun Hwang]

math_failure (math_image_error): \frac{x^2}{a^2}+\frac{y^2}{b^2}=1 is the equation for the shape of the lens (equestion of Ellipse).
Snell's law is used to calculate the ray refraction when light enter into lens and get out of the lens.
You should be able to find it in the code.

am i right to say that this simulation is to show us that the thicker the lens, the shorter the focal length?

Yes. The focal length getting shorter when lens is getting thicker.
When the lens is too thick or when the ray is too far from the axis, there might be a single focual point any more.
Please check out Lens (thick lens) and Mirror.