Optical storage: Laser diodes are used in devices such as CD, DVD, and Blu-ray players, where they read and write data by focusing a laser beam onto the surface of a spinning disc. Laser diodes power many devices we use daily. Diode laser technology drives a significant market, projected to hit USD 8. These devices are currently used in the fields of telecommunications and medicine and in industrial cutting and welding applications. This article discusses the characteristics common to laser. The history of alloy diode laser development and mass production for optical storage systems at Sony Corporation are reviewed in this paper.