491-nm ZnCeSe/ZnSe/ZnMgSSe SCH Laser Diode with a Low Operating Voltage

Room temperature pulsed operation of ZnCdSe/ZnSe/ZnMgSSe separate-confinement heterostructure lasers has been achieved at a wavelength of 491 nm, which is the shortest wavelength at room temperature ever reported. The laser structure was made by molecular beam epitaxy on n-GaAs substrate. The operating current density was 3.8 kA/cm2 for a diode with a 720 µm long and 10 µm wide stripe. An operating voltage of 9 V has been obtained at the threshold current using improved contact layers and ohmic metals.