High-Power THz Quantum-Cascade VECSEL based Local Oscillator

NASA and NASA funded missions/instruments such as Aura/MLS (Microwave Limb Sounder), SOFIA/upGREAT and STO/STO-2 have demonstrated the need for local oscillator (LO) sources between 30 and 300 um (1 and 10 THz). For observations gt;2 THz, technologically mature microwave sources typically have microwatt power levels which are insufficient to act as LOs for a multi-element heterodyne receiver.LongWave Photonics is proposing to develop a high power, phase/frequency-locked, single mode, THz QC-VECSEL quantum cascade laser (QC-VECSEL) system with gt;2nbsp;mW cw power (estimated 5mW) at 77K at 3.4 THz and deliver it to NASA at the end of Phase II. QC-VECSELs operating at 4.7 THz band will also be investigated and will be delivered to NASA ifnbsp;the performance is suitable.nbsp;The system includes a THz QC-VECSEL gain chip based on metasurface gain structure with an integrated cavity adjustment structure. The VECSEL LO will be packaged in a high-reliability Stirling cycle cooler with modification to minimize vibration noise. The source couldnbsp;be frequency locked to a stable microwave reference with lt;100 kHz line width. Moreover, the unique tuning mechanism for QC-VECSEL could achieve 250 GHz of tuning at 4.7 THz, meeting the design requirement for future HERO instrument on Origins Space Telescope (OST).