This lesson, presented by the National Nanotechnology Infrastructure Network, covers the diffraction behavior of light waves. Students will discover how CDs and DVDs contain regularly spaced micrmeter sized features that act like diffraction grating. Using these items rather than commercially produced plan transmission gratings "enhances student interest in the activity and also opens up a discussion on the trend of improving storage capacity with the invention of Blu-ray and layered DVDs." Three Teacher Preparation Guides, two Student Guides, a PowerPoint presentation, and Next Generation Science Standards for the lesson are included.