By Carola Rutigliani

 An optical drive is a piece of equipment that uses a laser to read or write information on a disc.

 a Digital Versatile Disc (DVD) player, Blu- ray disc (BD) player, and Compact Disc (CD) players are considered optical drives even though they may not be in a computer system. BD player DVD player CD player

 The optical path makes an optical drive work. The optical path is composed of three components: -a laser : writes and reads the data. -lens : guides the laser across the surface of the disc. -a photodiode: detects light reflected off the disc’s surface.

 The drive also uses two servomechanisms: 1. one to maintain the proper distance between the disc and laser. 2. to make sure the laser is moving in a continuous spiral path.

 The rotational mechanism in an optical drive differs considerably from that of a hard disk drives.  The disc keeps a constant angular velocity (CAV), in other words a constant number of revolutions per minute (RPM).