Tunable quantum-cascade VECSEL operating at 1.9 THz

We report a terahertz quantum-cascade vertical-external-cavity surface-emitting laser (QC-VECSEL) emitting around 1.9 THz with up to 10% continuous fractional frequency tuning of a single laser mode. The device shows lasing operation in pulsed mode up to 102K in a high-quality beam, with the maximum output power of 37 mW and slope efficiency of 295 mW/A at 77 K. Challenges for up-scaling the operating wavelength in QC metasurface VECSELs are identified. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This study presents a terahertz quantum-cascade vertical-external-cavity surface-emitting laser (QC-VECSEL) with significant continuous frequency tuning and high efficiency. The device demonstrates laser operation in specific conditions with good performance, but challenges remain for extending the operating wavelength in QC metasurface VECSELs.