1550-nm Driven ErAs:In(Al)GaAs Photoconductor-Based Terahertz Time Domain System with 6.5 THz Bandwidth


ErAs:In(Al)GaAs superlattice photoconductors are grown using molecular beam epitaxy (MBE) with excellent material characteristics for terahertz time-domain spectroscopy (TDS) systems operating at 1550 nm. The transmitter material (Tx) features a record resistivity of 3.85 kΩcm and record breakdown field strength of 170 ± 40 kV/cm (dark) and 130 ± 20 kV/cm (illuminated with 45 mW laser power). Receivers (Rx) with different superlattice structures were fabricated showing very high mobility (775 cm2/Vs). The TDS system using these photoconductors features a bandwidth larger than 6.5 THz with a laser power of 45 mW at Tx and 16 mW at Rx.

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We acknowledge the Deutsche Forschungsgemeinschaft (DFG) for funding project PR1413/3-1 (REPHCON). We further thank Christoph Gleichweit (Menlo Systems) for the assistance with the optical system and John Bowers for the partial support of the project.

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Correspondence to U. Nandi.

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Nandi, U., Norman, J.C., Gossard, A.C. et al. 1550-nm Driven ErAs:In(Al)GaAs Photoconductor-Based Terahertz Time Domain System with 6.5 THz Bandwidth. J Infrared Milli Terahz Waves 39, 340–348 (2018). https://doi.org/10.1007/s10762-018-0471-9

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  • Terahertz pulse
  • Photoconductor
  • Time domain spectroscopy (TDS)
  • Rare earth