Diffraction gratings made optical laser disc media possible. https://en.wikipedia.org/wiki/Diffraction_grating#Examples https://en.wikipedia.org/wiki/Diffracti

Diffraction gratings made optical laser disc media possible. https://en.wikipedia.org/wiki/Diffraction_grating#Examples https://en.wikipedia.org/wiki/Diffraction_grating#Examples https://electronics.howstuffworks.com/cd.htm https://electronics.howstuffworks.com/cd.htm http://physics.randolphcollege.edu/lab/106_116lab/Laser/CD.htm http://physics.randolphcollege.edu/lab/106_116lab/Laser/CD.h...