Abstract

Tunneling-time measurements on a heterojunction double-barrier resonant tunneling diode (RTD) have been made using electro-optic sampling techniques. Quantum- mechanical tunneling in these single quantum wells is the fastest known charge-transport mechanism in semiconductors. This class of device exhibits such features as negative differential resistance (NDR), an extremely fast current response,¹ and a high-frequency output when applied as an oscillator.² Now, using a laser-based sampling system having a demonstrated subpicosecond temporal response,³ a switching time of less than 2 ps has been measured for a double-barrier RTD. This measurement indicates the potential utility of these diodes as high-speed logic devices⁴ and helps explain the tunneling mechanisms involved.

© 1988 Optical Society of America