Simple diffraction grating experiments can be made using a compact disk as a diffraction grating. This diffraction grating can be used as an alternative to standard diffraction gratings in physics experiments. The diffraction grater is made up of a narrow gap that is adjacent to each other in large quantities. A beam of coherent light is passed through a diffraction grating it will produce a diffraction pattern on the screen. This diffraction grating experiment is used to determine the magnitude of the diffraction grating constants (d)and the capacity of the compact disk data.Variations of diffraction gratings are used using compact disk and Digital Versatile Disk. Coherent light from a laser with a wavelength of 365 nm is transmitted through a compact disk and Digital Versatile Disk. With variations of the grating distance to the screen (y)a bright dark pattern is generated on the screen. The light dark pattern is a diffraction phenomenon.the analysis of the calculation of diffraction grating laser pointer gained wide or CD lattice constants of (2800.1 ± 8.81)nm with a relative error 8.81%, while the width of the grid or DVD lattice constants of (1921.4 ±1.76) nm with a relative error of 1.76%. the capacity of CD earned as much as 226 Mb CD and capacity DVD earned as much as 480 Mb. Therefore, DVDs and CDs can be used as a diffraction grating. Through experiments laser diffraction grating can be calculated capacity of CD/DVD.
