Operation of a monolithic planar schottky receiver using a THz quantum cascade laser

This paper presents heterodyne mixer measurements at 2.9 THz using quantum cascade lasers (QCLs) as sources. The linewidth of the laser was explored by biasing it to run in dual mode operation and observing the linewidth of the beat note. In addition the frequency of the QCL is determined by beating it against a deuterated methanol line from a molecular gas laser.