When the optical storage medium is written, the dye is burned by the laser beam at a wavelength of 780 nm to 790 nm. The dye discolors under the resulting heat effect and thus changes the reflective behavior at this point.
Manufacturers use different materials that differ in their molecular structure and molecular bonding. For example, Mitsui uses phthalocyanine, which is characterized by a ring-shaped molecular structure and strong molecular bonding. Other manufacturers use azo or cyanine.