Abstract-Terahertz emission from a weakly-coupled GaAs/AlGaAs superlattice biased into three different modes of current self-oscillations

AIP Advances

G. K. Rasulova,  I. V. Pentin,  G. N. Goltsman

Electroluminescence spectrum of three coupled SL mesas (black line) measured at 8 K. Inset displays the reference square pulses of 1 V height and 330 Hz repetition rate (blue) and the pulsed current response (yellow) where the self-oscillations of current appear in half a period of the applied pulses. The EL spectrum of the SL sample with two coupled mesas11 is shown by blue line.

https://aip.scitation.org/doi/10.1063/1.5116014

Radio-frequency modulated terahertz (THz) emission power from weakly-coupled GaAs/AlGaAs superlattice (SL) has been increased by parallel connection of several SL mesas. Each SL mesa is a self-oscillator with its own oscillation frequency and mode. In coupled non-identical SL mesas biased at different voltages within the hysteresis loop the chaotic, quasiperiodic and frequency-locked modes of self-oscillations of current arise. THz emission was detected when three connected in parallel SL mesas were biased into the frequency-locked and quasiperiodic modes of self-oscillations of current, while in the chaotic mode of those it falls to the noise level.