Hilbert-transform spectroscopy with high-T/sub c/ Josephson junctions: first spectrometers and first applications

First laboratory prototypes of Hilbert-transform spectrometers have been developed. To meet the requirements of Hilbert-transform spectroscopy, high-T/sub c/ Josephson junctions with RSJ-like behavior have been fabricated on twin-free NdGaO/sub 5/ bicrystal substrates. The operation of the spectrometers has been demonstrated from 60 GHz up to 2.25 THz. The first out-of-lab application of Hilbert-transform spectrometers has been successfully demonstrated at the TESLA Test Facility linear accelerator at DESY (Hamburg). The spectra of coherent transition electromagnetic radiation from electron bunches have been measured and a bunch length of /spl sigma//sub t/=1.2 ps has been derived from these spectra. The market perspectives for Hilbert spectrometers have been estimated.