First ultra-low threshold continuous-wave lasing in GeSn

Transistors in computer chips work electrically, but data can be transmitted more quickly with light. Researchers have therefore been looking for a way to integrate a laser directly into silicon chips for a long time. A team of physicists at the Centre de Nanosciences et de Nanotechnologies (C2N), in collaboration with researchers at Germany's Forschungszentrum Jülich (FZJ) and STMicroelectronics, have implemented a new material engineering method to fabricate a laser microdisk in a strained germanium-tin (GeSn) alloy. They have demonstrated the laser device with a group IV compound, compatible with Silicon, operating with ultra-low threshold and under continuous-wave excitation.