A Numerical and Experimental Butt-Coupling Analysis of GaSb Diode Laser Grown on Silicon Photonic Integrated Circuit

Nowadays, Silicon (Si) photonics represents the most mature technology enabling low-cost Photonic Integrated Circuits (PICs). The approach based on the monolithic integration, i.e. by direct epitaxy, of III-V lasers on Si PICs opens new avenues for low-cost and high integration density of light sources on Si wafers. In this work, we study both theoretically and experimentally the optical coupling efficiency between a 2.3 μm GaSb diode laser (DL), epitaxially grown on on-axis Si (001) [1], and passive SiN waveguides (WGs) in the butt coupling configuration. Alternative approaches to improve the light transmission are also proposed.