Abstract: We report on a GaAs/AlAs superlattice detector as anovel direct detector and autocorrelator for THzradiation. It is based on a doped wide-minibandGaAs/AlAs superlattice, with submonolayer AlAs barrierlayers; the superlattice is operated at roomtemperature. THz radiation, generated by afree-electron laser and a mode locked p-Ge laser, wascoupled into the superlattice via a corner cube antennasystem. THz-irradiation of the biased superlatticeresulted in a current reduction, which was monitored.The direct detector showed a fast response (20 ps,limited by the electronic circuit) and was robustagainst intense radiation pulses (peak power 10 kW).The responsivity was 100 times higher than theresponsivity of detectors of comparable risetime andcomparable robustness. Intense THz radiation caused acomplete suppression of the current through thesuperlattice. This is the basis of the superlatticeautocorrelator. The superlattice autocorrelator couldresolve picosecond radiation pulses.!21
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