Patch Antenna Microcavities THz Quantum Cascade Lasers

We study the emission of THz quantum cascade lasers (QCLs) designed in arrays of Patch Antenna Microcavities (PAM). The array geometry is an effective strategy to control the losses and to achieve phase locking, allowing for beam shaping and high photon outcoupling efficiency. We demonstrate a 40-fold enhanced emission compared to standard ridge waveguides and a gaussian beam divergence as low as 2° × 2°.