Fig. 1. Schematic of internal and external cavity structures of tunable dual-wavelength laser

Fig. 2. Structure of sample and AFM photograph of indium-rich clusters

Fig. 3. Fixed wavelength is 974 nm and tuned wavelength is 969.1–977.9 nm

Fig. 4. ASE spectrum obtained by experiment（dashed line）and ASE spectrum obtained by theoretical calculation（solid line）

Fig. 5. Special energy band structure in quantum-confined structure of indium-rich clusters