Cascade lasers epitaxially grown on Silicon substrates

International audienceThe direct epitaxy of III-V lasers on Silicon (Si) substrates has been considered for decades as an important objective for the realization of integrated photonics chips. However, the difference in crystal structure, lattice-constant, thermal expansion coefficient as well as issues related to the reactivity of the Si surface have made this topic extremely challenging. For that reason, the direct epitaxy of lasers having good performance and decent lifetime on Si was considered as an almost unattainable dream, and many labs and companies have thus developed ways to circumvent this issue using hybridization techniques. Very recently, major progress has been achieved however thanks to a better understanding of the defect generation mechanisms and systematic studies of their suppression or at least the drastic reduction of their density into the active region of the device. In this presentation, we will discuss the challenges related to the growth of III-V on Si as well as the progress made lately in that field. We will then discuss the current state-ofthe-art of III-V lasers grown on Si with a focus on IR Interband and Quantum Cascade lasers. We will show that the most recent devices have as good performance as their counterpart grown on their native substrates, which opens the way for integration into photonic chips