Fig. 1. A germanium tin alloy with 22.3% tin composition by CVD epitaxy^［5］

Fig. 2. Spectral response and imaging result of Ge_0.80Sn_0.20 photoconductor^［22］

Fig. 3. Schematic diagram and relationship between responsivity and wavelength under different bias voltages of the Ge_0.89Sn_0.11 photodiode^［23］

Fig. 4. Spectral response of Ge_0.998Pb_0.002 photodetector for different temperatures^［14］

Fig. 5. Optically pumped F-P cavity germanium tin laser^{［28，30-31］}

Fig. 6. Optically pumped microdisk germanium tin laser^［35］

Fig. 7. Electrically pumped F-P cavity germanium tin laser^［36］