Experiment 11: CD Diffraction

Purpose: to figure out the distance beween the grooves on a CD using diffraction methods.

Equipment:

• Laser
• CD
• Meter stick(2)
• Clamps
• White board

Experiment:

The laser was arranged to shine a beam through the hole in a screen and strike the compact disk, a distance of ~0.5 meters.

The beam was perpendicularly striking the disk at a place where the grooves were tangentially vertical with the first order maxima.

Once the diffraction pattern appeared, the distance between the maxima was measured using the a smaller ruler at a known fixed distance fromt he CD.


Conclusion:

Based on the calculations made in this experiment, the distance of the grooves are 1535nm apart, which is a close answer to 1600nm with a 4.06% error