Temperature Dependent Terahertz Output from Semi-Insulating GaAs Photoconductive Switches
A G. Markelz, Edwin J. Heilweil
The temperature dependence of the terahertz (THz) output power and spectra from biased photoconductive switches was measured for several antenna gap widths and applied biases. The spectrally integrated THz output had a nonmonotonic temperature dependence in all cases with the values increasing by a factor of 3 from room temperature to 150 K for low biases and 100K at high biases. An abrupt decrease in output power occurs below 90 K, and the spectrum shifts to lower frequencies as the temperature is lowered.