(Invited) Toward GeSn Lasers: Light Amplification and Stimulated Emission in GeSn Waveguides at Room Temperature

Abstract

Waveguides were fabricated from n-type doped GeSn layers with Sn content in the range 4.4-7.0 % Sn grown on Ge-buffered Si substrates. The waveguides were optically pumped a 976nm continuous wave laser, and their power output was measured as a function of pump power. The output power dependence indicates light amplification through stimulated emission, and that GeSn acts as a gain medium. Under the experimental conditions, the cavity gain did not exceed the lasing threshold, but amplified spontaneous emission was still observed. This demonstration of optical gain at room temperature is an important first step to achieving room temperature lasing in GeSn.