Dynamic Mapping of Thermoelastic Strain in SiGeSn Laser During Operation

(Si)GeSn is a promising material platform for CMOS optoelectronics, as it exhibits a direct bandgap and can be epitaxially grown on Silicon wafers. The performance of SiGeSn lasers is limited by heating of the device during operation, the exact mechanism of which remains elusive. We aim to gain insight into the spatial and temporal distribution of heat nside a functional SiGeSn microlaser by mapping changes of the lattice strain while it is electrically pumped. For this, we will employ stroboscopic Full-Field X-ray Diffraction Microscopy at ID01, linking the frequency of the pumping to the bunch clock in a pump-probe setup. The use of a gated X-ray detector will allow us to pick a measurement period corresponding to the relaxation time of the lattice after pulsing. The results will be utilized in the development of a FEM model that allows us to extract thermal and electronic parameters relevant for device performance