CD-ROM

CD-ROM that exist today are generally made from resin (polycarbonate) and coated with highly reflective surfaces such as aluminum. The information is digitally recorded as microscopic pits on a reflective surface. This process is carried out using high intensity laser. A perforated surface is then coated by a layer of nodes. Information read by using low-intensity laser that illuminates the translucent layers rotate the disc while the motor. Then the laser intensity was changed after hitting the holes are then reflected and detected by fotosensor are then converted into digital data. Writing the data on CD-ROM can only be done once only. Nevertheless, the optical disk has the advantage in terms of mobility. Its small and thin makes it easier to carry anywhere.