The Blue Laser Diode: GaN based Light Emitters and Lasers

The development of a blue semiconductor laser on the basis of GaN by Shuji Nakamura opens a new field for the applications of semiconductor lasers. The wavelengths can be tuned by controlling the composition. For the first time in one substrate material, lasers with various wavelenghts, ranging from red through yellow and green to blue, can be formed. This fact together with their high efficiency make GaN based lasers very useful for a wide spectrum of applications. Additionaly, the realization of a unique and successful concept of research and development is discussed.