Wavelength coverage expansion in GaN‐based laser diodes

Abstract

Almost eight years has passed since the initial development of GaN‐based violet laser diodes (LDs) in the 405 nm wavelength range in 1995. Starting with next‐generation high‐density optical discs, the commercial use of violet LDs has been adopted in many new fields, such as biomedical, reprographic, and exposure fields. Recently, lasing wavelength has broadened to cover from the ultraviolet (UV) to blue‐green regions, which enabled other new applications. In this paper, the current status of GaN‐based LDs from the UV to blue‐green regions is reported and the next research target is discussed.