Phase-locking of a 4.7 THz quantum cascade lasers based on a harmonic super-lattice mixer

摘要

For heterodyne spectroscopy in the super-THz (～2-6 THz) there are currently few solid state local oscillator (LO) sources available. Since the introduction of the first THz quantum cascade laser (QCL) much progress has been made in pushing QCLs to higher frequencies, increasingoutput power and improving the far-field beam profile making the QCL increasingly well suited as a heterodyne LO. QCLs have been demonstrated in THz heterodyne receivers at frequencies up to 4.75 THz where the astronomically significant neutral atomic oxygen [OI] line is situated.