Mid-infrared quantum cascade lasers grown by MOCVD

Varying-composition, deep-well quantum cascade laser (DW-QCL) structures are proposed to suppress carrier leakage at and above room temperature. The layer compositions of the quantum wells and barriers in the active region differ from those in the extractor/injector regions. These structures are grown by using metal-organic chemical vapor deposition (MOCVD). Fabricated ridge-guide devices, lasing at ~ 4.8 μm, show ultra-low temperature sensitivity of their electro-optical characteristics by comparison to those of conventional QCLs emitting in the 4.5 - 5.5 μm wavelength range.