Current Status, and Future of Research on Optical and Electrical Semiconductor Devices

"How big revolution optical devices consisted of semiconductors can bring in society" is exemplified by using devices and materials which the author directly developed. The distributed feedback (DFB) laser diode has been used for the worldwide optical communications systems. A blue light-emitting-diode (LED) has been used as a light source for a white LED. The nitride semiconductor constructing a blue LED has also constructed a high electron mobility transistor (HEMT) as an amplifier in the base station of cellar phones.