hide
Free keywords:
LOW-TEMPERATURE GAAS; PHOTOCONDUCTIVE ANTENNAS; TECHNOLOGY; LIFETIMES;
EMISSIONOptics;
Abstract:
We demonstrate continuous wave (CW) terahertz generation from antennas fabricated on C-12-irradiated semi-insulating (SI) GaAs substrates. The dark current drawn by the antennas fabricated on irradiated substrates is similar to 3 to 4 orders of magnitude lower compared to antennas fabricated on un-irradiated substrates, while the photocurrents decrease by only similar to 1.5 orders of magnitude. This can be attributed to the strong reduction of the carrier lifetime that is 2.5 orders of magnitude, with values around tau(rec) = 0.2 ps. Reduced thermal heating allows for higher bias voltages to the irradiated antenna devices resulting in higher CW terahertz power, just slightly lower than that of low-temperature grown GaAs (LT GaAs) at similar excitation conditions. (C) 2015 Optical Society of America
