Ultrafast Sampling of a Dual-Gate Field-Effect Transistor

Measurement of semiconductor devices at frequencies ≥1THz will allow direct access to the dynamics of non-equilibrium carrier transport. At present, the fastest devices such as high electron-mobility transistors operate at frequencies <1THz but significantly greater than the ≈100GHz bandwidth of conventional electronic measurements.1 The reliability of extrapolating low-frequency measurements into the near-THz regime is unproven, and there is an increasing need for direct measurement methods in the 100GHz to 1THz frequency range.