High efficiency low threshold current 1.3 μm InAs quantum dot lasers on on-axis (001) GaP/Si

We demonstrate highly efficient, low threshold InAs quantum dot lasers epitaxially grown on onaxis (001) GaP/Si substrates using molecular beam epitaxy. Electron channeling contrast imaging measurements show a threading dislocation density of 7.3 x 10(6) cm(-2) from an optimized GaAs template grown on GaP/Si. The high-quality GaAs templates enable as-cleaved quantum dot lasers to achieve a room-temperature continuous-wave (CW) threshold current of 9.5 mA, a threshold current density as low as 132 A/cm(2), a single-side output power of 175 mW, and a wall-plug-efficiency of 38.4% at room temperature. As-cleaved QD lasers show ground-state CW lasing up to 80 degrees C. The application of a 95% high-reflectivity coating on one laser facet results in a CW threshold current of 6.7 mA, which is a record-low value for any kind of Fabry-Perot laser grown on Si. Published by AIP Publishing.