Frequency dependence of the harmonic radiation power emitted by a GaAs/AlAs superlattice diode in the terahertz frequency range

We present an experimental study of the harmonic radiation power in the terahertz frequency range emitted by a novel superlattice structure tested at room temperature. The superlattice diodes were pumped with fundamental frequencies in the range of 100-240 GHz. We measured the power spectrum of the harmonic output signal above 600 GHz using a Fourier transform spectrometer (FTS) in Groningen and with a terahertz spectrometer for molecular spectra in Cologne. We demonstrate the successful application of the SL-THz multiplier to record rotationally absorption spectral lines of deuterated (heavy) water D₂O up to the frequency of 2.7 THz with high accuracy.