Superlattice nonlinearities for gigahertz-terahertz generation in harmonic multipliers

0538979 - FZÚ 2021 RIV DE eng J - Journal Article
Apostolakis, Apostolos - Pereira, Mauro Fernandes
Superlattice nonlinearities for gigahertz-terahertz generation in harmonic multipliers.
Nanophotonics. Roč. 9, č. 12 (2020), s. 3941-3952. ISSN 2192-8606. E-ISSN 2192-8614
R&D Projects: GA ČR GA19-03765S
Institutional support: RVO:68378271
Keywords : asymmetric current flow * high harmonic generation * interfaces * semiconductor superlattices
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 8.449, year: 2020
Method of publishing: Open access

Semiconductor superlattices are strongly nonlinear media offering several technological challenges associated with the generation of high-frequency Gigahertz radiation and very effective frequency multiplication up to several Terahertzs. However, charge accumulation, traps and interface defects lead to pronounced asymmetries in the nonlinear current flow, from which high harmonic generation stems. This problem requires a full non-perturbative solution of asymmetric current flow under irradiation, which we deliver in this paper within the Boltzmann-Bloch approach. We investigate the nonlinear output on both frequency and time domains and demonstrate a significant enhancement of even harmonics by tuning the interface quality. Moreover, we find that increasing arbitrarily the input power is not a solution for high nonlinear output, in contrast with materials described by conventional susceptibilities. There is a complex combination of asymmetry and power values leading to maximum high harmonic generation.

Permanent Link: http://hdl.handle.net/11104/0316710