Lasers and White Light
Safety Warnings
Warning: Laser Eye Hazard
Warning: Projector Heat Warning
Purpose
Compares diffraction of three individual laser wavelengths (red, green, blue) with white light from a slide projector through the same grating. Students see discrete laser spots at specific angles alongside the continuous rainbow spectrum from white light, demonstrating that white light contains all visible wavelengths.
Figure 1:
Zeroth-order white light stripe (left) and first-order spectrum with discrete laser spots (blue, green, red) overlaid on the continuous rainbow from the projector.
Figure 2:
Slide projector and three lasers aligned to pass through the same diffraction grating, with zeroth-order and first-order patterns visible on the screen.
Figure 3:
Slide projector elevated on wooden platform with three lasers mounted behind it. The diffraction grating sits near the table edge.