We analyzed the efficiency of coherent scattering of infrared radiation in atomic and molecular gases for production of intense short THz pulses, using simulated Raman adiabatic passage (STIRAP). The method is based on excitation of maximal coherence when the system is undergoing through STIRAP in IR-irradiated atomic or molecular gases (for example Rb, methanol, and others) at room temperature. By applying optical pulses in correct sequence one can generate coherence in a system during STIRAP which triggers following coherent scattering of infra-red radiation, and can produce pulses of THz radiation with pulse energies ranging from several nJ to µ-J and pulse durations from several fs to ns.

Quantum Hall (QH) systems can work as very sensitive THz detectors. In this work we report on the spectral and temporal resolution of the QH THz photodetectors with different geometries. The spectral resolution of THz QH detectors is of the order of 1-3 meV depending on bias conditions. The temporal resolution of QH detectors depends on the device geometry. For Corbino-shaped detectors we have demonstrated the devices with response times from 10 ns to over 200 ns.