ZnMgSSe/ZnSe/CdSe quantum dot heterostructures for green laser applications

Cd(Zn)Se/ZnSSe/ZnMgSSe laser heterostructures with an asymmetrical ZnSSe/ZnSe supperlattice waveguide, and multiple (up to 9) electronically-coupled CdSe quantum dot sheets in the active region were designed and grown by molecular beam epitaxy. Internal quantum efficiency ηi, internal loss αi, transparency threshold JT and characteristic gain ΓG0 were found to be: 58.5%, 7 cm− 1, 1.78 kW/cm2, and 194 cm− 1, respectively, in a laser heterostructure with 9 electronically-coupled CdSe quantum dot active layers. A violet-green integrated laser converter with the output pulse power up to 50 mW was fabricated on the basis of the Cd(Zn)Se/ZnSSe/ZnMgSSe quantum dot laser heterostructure. The heterostructures were optically pumped by emission of a violet (λ = 416 nm) commercial InGaN/GaN pulsed laser diode. The ways for further laser threshold reduction and increasing the efficiency are discussed.