“…Ohmic contacts are formed on the surface of circular mesas with AuGe/Ni/Au metallization for current-voltage (I-V) characterization, which is used for InP:Fe resistivity calculation. SI-InP regrowth by HVPE was implemented in BH QCL fabrication for double metal waveguide THz micro-pillar array QCL, reverse-tapered high power 4.6 µm QCL 17 and high speed 9.15 µm distributed feedback (DFB) QCL. The performance of fabricated BH QCL devices was characterized systematically.…”