Project: Nano-Ridge Engineering for Densely Integrated IIIV Lasers Directly Grown on Silicon

2020-09-01 – 2026-08-31

Abstract

Although Silicon Photonics, i.e. using mature technologies from the CMOS-industry for realizing complex photonic ICs, progressed enormously, with industrial uptake by the biggest electronics manufactures, its real breakthrough, in e.g. large volume consumer applications or very short interconnects, is hampered by its lack of a true waferscale optical source. Combining aspect-ratio trapping, to suppress defects, and nano-ridge engineering, to shape the resulting material, we have developed a powerful platform to integrate direct bandgap III-V semiconductors on standard silicon wafers, using truly waferscale processes.  The exceptionally high quality of this material was confirmed through morphological studies, gain and lifetime measurements and the demonstration of lasing under optical pumping.  For practical applications, electrical injection is key though, which thus far has been elusive as the dimensions of the resulting GaAs/InGaAs nano-ridges are too small to directly apply electrical contacts without introducing unacceptable losses. Therefore, NARIoS’ primary objective is to propose device concepts that overcome the trade-off between optical confinement and efficient current injection.  We aim at the demonstration of electrically injected microcavity lasers for low-power applications and the demonstration of a novel class of mW-lasers with in-plane or out-of-plane emission, exploiting the possibility to grow highly uniform arrays of these nano-ridges. Next, we aim to demonstrate single photon emission from long-wavelength InAs-quantum dots grown on the nano-ridge platform, eventually integrated in a suitable microcavity. These device-oriented objectives will be complemented by two transversal objectives: development and extensive characterisation of InGaAs nano-ridges for extending the lasing wavelength and exploiting novel concepts from recent literature to design lasers resilient to optical feedback and/or exhibiting lasing in a single coherent spatial mode.