Pattern for Newton's Ring

This simulation is created due to the following request from Re: Effect of a Medium on a Double Slit Interference Pattern

Quote

dear sir
the interference simulations on introdusing a medium inthe path really superb
why dont you try measurement in newtons rings?
best wishes
raman

The following message is from http://en.wikipedia.org/w/index.php?title=Newton's_rings

The phenomenon of Newton's rings, named after Isaac Newton, is an interference pattern caused by the reflection of light between two surfaces - a spherical surface and an adjacent flat surface. When viewed with monochromatic light it appears as a series of concentric, alternating light and dark rings centered at the point of contact between the two surfaces. When viewed with white light, it forms a concentric ring pattern of rainbow colors because the different wavelengths of light interfere at different thicknesses of the air layer between the surfaces. The light rings are caused by constructive interference between the light rays reflected from both surfaces, while the dark rings are caused by destructive interference. Also, the outer rings are spaced more closely than the inner ones. Moving outwards from one dark ring to the next, for example, increases the path difference by the same amount λ, corresponding to the same increase of thickness of the air layer λ/2. Since the slope of the lens surface increases outwards, separation of the rings gets smaller for the outer rings.

The radius of the Nth Newton's bright ring is given by $r_N= \left[\left(N - {1 \over 2}\right)\lambda R\right]^{1/2}$

(image from http://scienceworld.wolfram.com/physics/NewtonsRings.html)
$r^2+(d-R)^2=R^2$ , so $d=\sqrt{R^2-r^2}$
Reflection from hemisphere undergoes a phase change of $\Delta \phi=0$ . Reflection from the plane gives a phase change of $\Delta \phi=\pi$ .
The phase difference between rays reflected off the plane and hemisphere is therefore
$\delta=k(2d)-\pi=\frac{4\pi n d}{\lambda}-\pi$ for $d<<R$ , and the interference pattern goes as $\cos^2\delta$
where $n$ is the index of refraction.

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

Please feel free to post your ideas about how to use the simulation for better teaching and learning.
Post questions to be asked to help students to think, to explore.
Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

Related Topics
	Subject	Started by	Replies	Views	Last post
	Interference pattern in a wedge shaped case Optics	Fu-Kwun Hwang	1	25632	August 19, 2009, 09:40:10 pm by Fu-Kwun Hwang
	what is the voltage across the split ring commutator when the loop is rotating? Question related to Physics or physics related simulation	lookang	4	14959	March 05, 2010, 09:09:20 pm by HY
	Wave bounced from the boundary and the interference pattern wave and fluid	ahmedelshfie	0	4117	May 25, 2010, 08:36:16 pm by ahmedelshfie
	Magnet Falling Through Ring Model Simulations from other web sites	ahmedelshfie	0	5072	September 13, 2010, 06:02:09 pm by ahmedelshfie
	Interference pattern from two sets of circular rings Optics	Fu-Kwun Hwang	0	6574	January 10, 2011, 07:36:33 am by Fu-Kwun Hwang

	Author	Topic: Pattern for Newton's Ring (Read 16660 times)
0 Members and 1 Guest are viewing this topic. Click to toggle author information(expand message area).