Multifrequency terahertz-wave emission and detection with the photomixing approach: theory and experiments

Florin Lucian Constantin (1)

1 PhLAM - Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523

This contribution addresses theoretically and experimentally the photomixing signal in a low-temperature-grown GaAs (LTG-GaAs) device with a planar antenna that is driven with an alternative electric field superposed on a bias electric field. The total electric field is applied on the optically-driven nonlinear photoconductance of LTG-GaAs. A theoretical framework based on unidimensional carrier transport is developed to calculate the amplitudes and the phases of different spectral components of the current density. Radiofrequency modulation of the photomixing signal in the microwave domain is experimentally demonstrated. Conversely, the photomixer is exploited as an optically-driven detector. Heterodyne detection with a photomixer is experimentally demonstrated with modulated THz-waves. The photomixing approach allows to extract THz modulation parameters by measurements with a modulated optical beat.

Mots clés: low-temperature-grown GaAs photomixer; optical frequency down-conversion; THz frequency comb; THzwave modulation; THz-wave direct detection; THz-wave heterodyne detection

Domaines: Optique [physics.optics]; Instrumentations et Détecteurs [physics.ins-det]; Micro et nanotechnologies/Microélectronique

Florin Lucian Constantin. Multifrequency terahertz-wave emission and detection with the photomixing approach: theory and experiments. Terahertz Photonics, Apr 2020, Strasbourg, France. pp.2555526, ⟨10.1117/12.2555526⟩. ⟨hal-03054146⟩