CREOL: CROL-103 | and Virtual Title: Terahertz metasurface quantum-cascade vertical-external-cavity surface-emitting-lasers (VECSELs) Abstract: The terahertz frequency range lies at the junction of the electronic and photonic regimes, which means that it is fertile ground for exploring hybrid systems which combine laser gain with microwave electromagnetic design. The terahertz quantum-cascade (QC) laser is an excellent example, which produces gain via intersubband electronic transitions within heterostructure quantum …