ErAs:In(Al)GaAs photoconductor-based time domain system with 4.5 THz single shot bandwidth and emitted terahertz power of 164 µW
Uttam Nandi, Katja Dutzi, Anselm Deninger, Hong Lü, Justin Norman, A. C. Gossard, Nico Vieweg, Sascha Preu
Abstract
Superlattice structures of In(Al)GaAs with localized ErAs trap centers feature excellent material properties for terahertz (THz) generation and detection. The carrier lifetime of these materials as emitter and receiver has been measured as 1.76 ps and 0.39 ps, respectively. Packaged photoconductors driven by a 1550 nm, 90 fs commercial Toptica "TeraFlash pro" system feature a 4.5 THz single shot bandwidth with more than 60 dB dynamic range. The emitted THz power of the ErAs:In(Al)GaAs emitter versus laser power has been recorded with a pyroelectric detector calibrated by the Physikalisch Technische Bundesanstalt (PTB). The maximum power was 164 µW at a laser power of 42 mW and a bias of 200 V.