Wideband THz Local Oscillator

In NASArsquo;s 2019 Astrophysics Biennial Technology Report ldquo;tunable-bandwidth array receivers for operation at frequencies of 1 ndash; 5 THz,rdquo; is described as a tier 2 technology gap priority [1].nbsp; Specifically, there is a need ldquo;for LO [local oscillator], sources with output power levels ge; 10 micro;W at frequencies above 2 THz,rdquo; pumping ldquo;arrays of 10 to 100 pixels.rdquo;nbsp; THz Quantum Cascade Lasers are excellent candidate LOs in this frequency range because of their multi-milliwatt power levels, necessary to pump pixel arrays of superconducting hot electron bolometer mixers, as well as room temperature Schottky diode mixers.nbsp; Recently, demonstrations of QCLs emission spanning 1.6 to 4.5 THz suggests the possibility of a WIdeband LO (WITLO).nbsp; nbsp;In this work LongWave will develop mode matching structures to provide effective anti-reflection coatings for its QLCs.nbsp; This will enhance output power and wall plug efficiency of its lasers, and enable external cavity tuning.nbsp; LongWave will develop specifications and a design for integration of this QCL with amplitude stabilization as well as low SWaP cryocooling necessary for future NASA missions.