Study of the THz Oscillator Based on Josephson Junction and Comparative Review with THz Sources – Backward Wave Oscillator and Semiconductor-based Frequency Multiplier

A study of the output terahertz (THz) emission to open space from Nb/AlO x /Nb-based long Josephson junction (LJJ) was carried out. Both bolometric technique with a frequency resolution of about1 GHz and heterodyne technique with spectral resolution of about 0.1 MHz were used for detection of the THz emission. A comparative analysis with other types of THz sources was made, such as backward wave oscillator (BWO) and frequency multiplier based on a semiconductor superlattice GaAs/AlAs with large harmonic numbers. A qualitative and quantitative comparison with respect to weight and size characteristics, the spectral properties, the emission power, as well as a general usability in laboratory conditions, was made. The highest detected power was achieved with an LJJ-based oscillator, and the most convenience was demonstrated using a superlattice-based oscillator with large harmonic numbers.