Switching operation of lasing wavelength in mid-infrared ridge-waveguide quantum cascade lasers coupled with microcylindrical cavity

摘要

We demonstrated switching operation of lasing wavelength in GaAs-based mid-infraredncoupled-cavity quantum cascade lasers. Our cavity structures consist of a ridge-waveguide Fabry–nPerot cavity coupled with a microcylindrical cavity. Individual control of currents injected into bothncavities enabled single-mode operation and facilitated intentional mode switching betweenncoupled-cavity modes with spacing over 120 nm. The integrated microcylindrical cavity expandednthe separation of coupled-cavity modes due to the small size of the cavity and enabled switching thenlasing wavelength over a wide spectral range.