Hybrid integration of InAs/GaAs quantum dot microdisk lasers on silicon

In the last decades, significant efforts have been devoted to developing semiconductors III-V lasers on silicon substrates, due to the prospects for the implementation of the high-speed lasers for optical communication systems integrated with silicon electronics and transistor logic. Low-threshold ridge-waveguide and microdisk/microring lasers based on AlGaAs heterostructures with self-organizing quantum dots In(Ga)As grown on Si substrates were demonstrated [1] , [2] . However, lasers synthesized on silicon are still inferior to analogs grown on native substrates (GaAs) [3] , due to higher defect densities caused by differences in polarity, lattice constants and coefficients thermal expansion of III-V materials and silicon. The epitaxial growth of laser heterostructures on native substrates (e.g. GaAs) and subsequent transfer of ready-made microlasers to silicon can help to avoid problems associated with monolithic integration of III-V and Si. Ring and disk microlasers have attracted more and more attention and are considered as promising sources of emission for inter-chip data transmission. The advantages of such microcavities are the high Q-factor of the whispering gallery (WG) modes, small size and, accordingly, low threshold currents and power consumption. In this work we study integration of InAs/GaAs quantum dot microdisk lasers on silicon either retaining the native substrate or separating from the substrate using a sacrificial layer.