Generation of high-frequency radiation in semiconductor superlattices with suppressed space-charge instabilities

TL;DR

This paper presents a theoretical scheme for generating high-frequency microwave and THz radiation in semiconductor superlattices while suppressing space-charge instabilities, enabling efficient harmonic generation and parametric amplification.

Contribution

It introduces a novel theoretical approach to avoid destructive space-charge instabilities in superlattices, allowing strong high-frequency gain without relying on negative differential conductance.

Findings

Generation achieved at odd harmonics of the pump frequency

Negative differential conductance not required for gain

Limited space-charge does not significantly reduce gain

Abstract

We theoretically investigated the scheme allowing to avoid destructive space-charge instabilities and to obtain a strong gain at microwave and THz frequencies in semiconductor superlattice devices. Superlattice is subjected to a microwave field and a generation is achieved at some odd harmonics of the pump frequency. Gain arises because of parametric amplification seeded by harmonic generation. Negative differential conductance (NDC) is not a necessary condition for the generation. For the mode of operation with NDC, a limited space-charge accumulation does not sufficiently reduce the gain.