Optical disc drive beam on a smaller spot size and to read smaller pits. DVD lens supports a different focus for CD or DVD media with same laser. With the newer Blu-ray disc drives, the laser only has to penetrate 0.1 mm of material. Thus the optical assembly would normally have to have an even greater focus range. In practice, the Blu-ray optical system is separate from the DVD/CD system. During the times of CD writer drives, they are often marked with three different speed ratings. In these cases, the first speed is for write-once (R) operations, the second speed for re-write (RW)
Archival Disc data storage within the datacenter. Archival Disc Archival Disc (AD) is the name of a trademark owned by Sony Corporation and Panasonic Corporation describing an optical disc storage medium designed for long-term digital storage. First announced on 10 March 2014 and planned to be introduced in the second quarter of 2015, the discs are intended to be able to withstand changes in temperature and humidity, in addition to dust and water, ensuring that the disc is readable for at least 50 years. The agreement between Sony and Panasonic to jointly develop the upcoming generation optical media standard was first announced