CD Rainbow
Purpose
A CD's data tracks (spaced at \(1.6\,\mu\text{m}\)) act as a reflection diffraction grating, separating white light into a vivid spectral rainbow on the wall. Students see that periodic structures produce wavelength-dependent diffraction angles, distinct from prism-based dispersion.
Figure 1:
White light reflecting off the CD produces a rainbow spectrum on the wall (first-order diffraction) surrounding a bright central specular reflection.
Figure 2:
Closer light source produces a brighter, more saturated spectrum. The full visible range from violet to red is clearly separated.