半導体中の電子と音波の相互作用
超音波増幅の原理
1966 年 35 巻 8 号 p. 548-558
詳細
1966 年 35 巻 8 号 p. 548-558
The mechanism of ultrasonic amplification in piezoelectric semiconductors has been investigated by a good many scientists since this phenomenon was first observed by Hutson et al. in 1961. At the same time, current saturation and oscillation associated with the ultrasonic amplifica-tion have also been examined and many valuable results have been obtained. The investigation of these associated phenomena is very necessary to develop the ultrasonic amplifiers because the ultrasonic noise arises from these phenomena. The mechanism of ultrasonic amplification can be interpreted sufficiently by the classical theory based on the electron bunching model. On the other hand, the quantum treatments are needed to interprete current saturation and oscillation since these phenomena are quite complicated. The application of the ultrasonic amplifiers will soon become practical in various fields, for examples, electronic industry, medicine, research of physics etc. with the development of suitable materials and ultrasonic transducers of a high efficiency.
