Experiment 11: CD Diffraction

Introduction: This experiment investigates the phenomenon of light diffraction by using the grooves on a CD and diffraction to measure the spacing between the grooves.

Data:

Setup of apparatus used in this experiment.

Measurement of bright fringes in the experiment using a whiteboard.

Using a CD to find the width of the grooves on the disc.

Measurements made for the wavelength of the laser.

Conclusion:
Our experiment gave us results that prove diffraction is a reliable way of measuring the width of the grooves on a CD. The standard value for the width of a groove on a CD today is 1600 nm, which gives us a percent error of 16.3%. Our measured value is well within the accepted uncertainty.