Fig. 1. Schematic of optical signal amplification in an EDFA

Fig. 2. Schematic of 980 nm single-mode semiconductor laser chip

Fig. 3. Typical characteristic curves of a 980 nm single-mode semiconductor laser chip. (a) Optical output power and power conversion efficiency versus current (inset: chips photo); (b) slow-axis far-field profile under different currents (inset: near-field profile at 1500 mW)

Fig. 4. Optical power-current curves of 980 nm single-mode semiconductor laser chip under high injection current

Fig. 5. Typical characteristic curves of 980 nm single-mode coupling module. (a) Optical output power and fiber coupling efficiency versus current (inset: module photo); (b) spectra under various output powers

Fig. 6. Long life-time test curve of 980 nm single-mode laser chip under current of 2 A and junction temperature of 137 ℃