抄録
GaAs ultrafast photoconductive switches are reviewed from the point of view of their application to ultrafast photonic sampling of high-speed electron devices. The photoconductive switches are interdigitated metal-semiconductor-metal diodes fabricated on low-temperature grown GaAs which reveals femtosecond lifetime of photoexcited carriers. On the basis of ultrafast voltage transients of photoconductive switches, it is pointed out that the dispersion of signal transmission lines and the RC time constant due to electrode capacitance limit the ultrafast performance of the photoconductive switches. Monolithic integration technology is developed for the ultrafast photonic sampling. In this technology, photoconductive switches are connected with an electron device by high-speed waveguides. Fabrication of a nanometer-scale transistor integrated with photoconductive switches is described and ultrafast characteristics of the transistor is presented.
