680 nm CW operation at room temperature by AlGaAs double heterojunction lasers

Room temperature CW operation has been realized in the spectral range of 680-700 nm by AlGaAs double heterojunction (DH) lasers with novel structures. In order to reduce the compressive stress in the active layer, the GaAs substrate was removed after growing DH layers with a thick AlGaAs buffer layer. Furthermore, magnesium was used as the dopant for aluminum-rich p-cladding layer instead of germanium or zinc to obtain high conductivity. This laser is named the stress-free -channeled substrate inner stripe laser (the SF-VSIS laser). Low-threshold currents (45-120 mA) and the fundamental transverse and single longitudinal mode have been obtained under room temperature CW operation below 700 nm. The shortest CW wavelength is 683 nm at present.