TERAHERTZ RESPONSE OF AN INGAAS ALAS RESONANT-TUNNELING DIODE

We have measured the broad-band terahertz response of a state-of-the-a rt InGaAs/AlAs resonant tunnelling diode from 120 GHz to 3.9 THz using the free-electron lasers at the University of California, Santa Barba ra. A tungsten whisker antenna in a conventional probe station is used to couple the far-infrared radiation into the device. By normalizing the rectified response in the resonant tunnelling regime with the off- resonant response we are able to remove the antenna frequency effects and the frequency dependence controlled by the much slower RC time con stant and measure the relaxation time due to the quantum inductance.