In NASAs 2019 Astrophysics Biennial Technology Report tunable-bandwidth array receivers for operation at frequencies of 1 5 THz, is described as a tier 2 technology gap priority [1]. Specifically, there is a need for LO [local oscillator], sources with output power levels ? 10 µW at frequencies above 2 THz, pumping arrays of 10 to 100 pixels. 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. Recently, demonstrations of QCLs emission spanning 1.6 to 4.5 THz suggests the possibility of a WIdeband LO (WITLO). In this work LongWave will develop mode matching structures to provide effective anti-reflection coatings for its QLCs. This will enhance output power and wall plug efficiency of its lasers, and enable external cavity tuning. 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. Potential NASA Applications (Limit 1500 characters, approximately 150 words): NASA applications include the use of Wideband THz LO (WITLO) in a reduced sized package as an LO for >2 THz receivers for future SmallSat and space/weight/power constrained missions. Examples include ASTHROS, OST/HERO, a future instrument for SOFIA, as well as future Planetary missions for observation of gasses in the 2 to 5 THz range. A laboratory version of WITLO would be ideal for characterizing novel mixer technology (e.g. MgB2 mixers, novel Schottky diode receivers) as well as laboratory demonstrations of trace gas detection. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Initial applications are research markets for low-pressure gas spectroscopy. The narrow line width and the ability to provide real-time frequency information of THz radiation also has great appeal. For industrial applications, the use of high-reliability, compact Stirling coolers with integrated frequency and amplitude stabilization would increase the usability of these devices Duration: 6
