Spectral Shaping In Ultra-Thin Terahertz Quantum Cascade Laser Pairs

We present optically coupled episide down bonded ultra-thin terahertz quantum cascade wire laser pairs. Episide down flip chip bonding facilitates the electrical contacting of ultra-thin lasers. The resulting sandwich structure traps the radiation propagating outside the laser cavities. In subwavelength laser cavities up to half of the mode propagates along the outside. This radiation couples to the neighboring ridges which injection-locks them.