Room temperature emission spectroscopy of GeSn waveguides under optical pumping

Waveguides were fabricated from highly n-type doped GeSn layers with Sn content at 5.4%–6.2% and grown on Ge-buffered Si substrates. The waveguides were optically pumped using a 976 nm continuous-wave laser, and the waveguide emission spectrum was collected and analyzed. The results indicate a non-linear power increase via higher injection-level at room temperature. Comprehensive theoretical models for the waveguide emission power dependence were developed to reproduce experimental data and provide an understanding of the nonlinear power dependence.