It's difficult to pinpoint one specific inventor or date for the "optical disk" because the technology evolved over time. However, here's a breakdown of key milestones:

Early Concepts and Research (1950s-1960s):

* 1958: David Paul Gregg, an American physicist, filed a patent for a "System for Recording, Storing and Reproducing Information on a Rotating Disc". This is considered one of the earliest concepts for optical storage.

* 1960s: Research on laser technology and its potential for data storage began.

Early Prototypes (1970s):

* 1970s: Several researchers, including James Russell, worked on developing prototypes of optical disk systems.

Commercialization (1980s):

* 1982: Philips and Sony jointly announced the Compact Disc (CD) format, which was the first commercially successful optical disk technology.

* 1985: The first commercial CD player was released.

* 1985: Philips also introduced the CD-ROM format for data storage.

Further Developments (1990s-Present):

* 1995: The Digital Versatile Disc (DVD) format was introduced, offering higher capacity and improved performance.

* 2000s: Blu-ray Disc technology was introduced, providing even greater capacity and improved video quality.

Therefore, it's more accurate to say that the optical disk was developed gradually throughout the late 20th century, with key milestones in the 1970s leading to the commercialization of the technology in the 1980s.