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 k Omega cm 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 cm(2)/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.