Fig. 1. Epitaxial structure of 975 nm semiconductor laser. (a) Sample 1; (b) sample 2

Fig. 2. Influence of annealing temperature on wavelength blue shift

Fig. 3. Influence of annealing temperature on PL spectral intensity. (a) Sample 1; (b) sample 2

Fig. 4. Influence of annealing time on quantum well mixing. (a) Influence on wavelength blue shift; (b) influence on PL spectral intensity

Fig. 5. Concentrations of In atoms under different diffusion lengths