Fig. 1. (Color online) The schematic structure of the GaN-based blue LD chip. The ridge waveguide structure is 30 × 1200 μm².

Fig. 2. (Color online) Photoluminescence image in micro-scale of a GaN-based blue LD grown on GaN substrate.

Fig. 3. (Color online) (a) P–I–V curves of a GaN-based blue LD in C-mount package under continuous-wave operation at room temperature. (b) The optical spectrum of stimulated emission for a GaN-based blue LD under 500 mA continuous-wave operation at room temperature.