The compact disc is a small disc that can store digital data in the form of audio, video, text, photographs, music, etc. The CD burners have revolutionized the world of digital music. Collecting songs became very easy with it. However, with the advent of new technology and inventions in data storage devices, this technology has fallen behind.
It stores data in digital form. Digital data is represented in the form of 1s and 0s. These 1s and 0s are in the form of bumps and flat areas on the surface of a CD. They are ordered on a circular track, which is 0.5 micron thick and 3.5 miles long. The bump represents 0 and the flat represents 1, which are read with a laser beam in the CD player.
The laser beam is focused on the reflective surface of the CD and the reflected light is read using a light sensor in the CD player. The data is stored on the bumps in a spiral path that starts at the center. The disc rotates in the player so that the laser beam reads the bumps and flats on it. The CD burner has laser assembly to read and write the data.
Working of a CD Burner
It is used to form the bumps and flats on the CD. The CD is made of an aluminum layer and an acrylic layer over this aluminum layer. When they are manufactured, bumps and flats are engraved on the aluminum layer. The CD burners used in the computers use a laser beam to create the bumps and flats.
The CD-R also uses a laser beam, but the construction of these CDs is a bit different as compared to the ones that are written when they are manufactured. The aluminum layer is covered with a translucent dye. This layer does not have any bumps as in the CD that is manufactured in the factories.
In CD-R, the translucent dye turns opaque when the laser beam falls on it. The bumps are not formed physically, but optically. The opaque dye appears to be a bump for the laser that is used for reading.
The data on the RW is not permanent and this is the reason of its complexity. The CD-RW does not use the translucent dye. Instead, it uses a layer of phase-shift compound. This compound also turns opaque due to the laser that is used for writing. It remains opaque until it is heated again and becomes translucent upon reheating.
The process is carried out by the laser when the CD is burnt the next time. The phase-shift compound turns translucent at lower temperature of 200 degrees Celsius and turns opaque at 600 degrees Celsius.
It's in a crystalline state when translucent and opaque when it is amorphous. The CD burner erases the data by exposing a part of the CD or whole to high temperature with the help of a laser beam.