Abstract
Continuous-wave (CW) 640 nm operation at room temperature (20°C) has been achieved by a transverse-mode stabilised AlGaInP laser diode with an (Al0.15Ga0.85)0.5In0.5P quaternary active layer. The lasing wavelength is the shortest ever reported for room-temperature CW operation of semiconductor lasers. The laser structure was grown by metalorganic vapour-phase epitaxy. The threshold current (density) was 63 mA (4.2 kA/cm2).