Materials/Supplies
Access to computer and high-speed internet, Java installed on the computer
Time Spent
Approximately 2 hours, does not need to be done at one sitting
Learning Objectives
Describe diffraction of light and use the equations of diffraction theory to predict
diffraction patterns
First proceed to the following website to complete the lab:
Wave Interference
Once the page is open, you should see something like the screenshot below:
Figure #1
Before we begin experimenting with light, take a few minutes to watch the following video:
Wave Motion Interference
Keep the simulator on the first tab to experiment with creating water waves!
, The photograph below shows the interference of two water waves produced by two coherent
sources operating at the same frequency and in phase. The waves travel outward at a constant
speed from the two sources at the center bottom of the picture.
Figure #2
1. Describe the pattern produced by the interfering waves.
Answer:
The waves move outward in concentric circular patterns. Where the waves overlap, they
create an interference pattern through constructive and destructive interference depending on
how the crests and troughs align. Some regions show amplification and larger wave motion,
while other regions show little or no movement. This produces a diamond-like pattern in the
center along with ray-like lines radiating outward from the sources.
Now in the simulator, select the laser as the wave source by clicking the icon which looks like
the image below:
Once you turn on your green laser, it should look like this: