Two-Wavelength Quantum Cascade Lasers with Heterogeneous Cascades

Dual-wavelength Quantum Cascade (QC) lasers with heterogeneous cascades are presented. In QC-lasers with interdigitated cascades the active core consists of a stack of active regions and injectors designed for emission at 8.0 mum interleaved with a second stack emitting at 9.5 mum. Clear laser action at two substantially different wavelengths is observed, demonstrating the viability of this approach to achieve multi-wavelength laser emission in the mid-infrared.