CD recordable Disc is once written optical disc, the wavelength of the laser head is 780 nm, the highest supported speed is 52X, the maximum capacity of 700MB. Through CD-R burning driver beam down the dye layer, it forms pit and land which is light and shade for recording data. CD-R manufacturing technology: on a 1.2mm thick substrate with a groove, dye is coating in the groove, reflective layer is sputtering on the dye layer, outside the reflective layer also spin coating protection glue.