TEMPERATURE-DEPENDENT TERAHERTZ OUTPUT FROM SEMIINSULATING GAAS PHOTOCONDUCTIVE SWITCHES

The temperature dependence of the terahertz (THz) output power and spe ctra from biased photoconductive switches was measured for several ant enna gap widths and applied biases. The spectrally integrated THz outp ut had a nonmonotonic temperature dependence in all cases with the val ue increasing by a factor of 3 from room temperature to 150 K for low biases and 100 K at high biases. An abrupt decrease in output power oc curs below 90 K, and the spectrum shifts to lower frequencies as the t emperature is lowered. (C) 1998 American Institute of Physics.