Fig. 1. Schematic of the sectional refractive index distribution (left axis) and the optical NFP distribution (right axis). The inset shows the detail of the active region.

Fig. 2. Calculated conduction energy band diagram at different doping levels. The inset shows the ΔE_c between the waveguide layer and the p-cladding layer at different doping levels.

Fig. 3. (a) Dependence of calculated Γ, vertical divergence, and R_F/H on d_ME; (b) dependence of vertical divergence on d_n−cladding.

Fig. 4. Simulated far-field pattern (FFP) in the fast axis.

Fig. 5. (a) Cavity length dependence of the inverse external differential quantum efficiency; (b) threshold current density versus the inverse cavity length.

Fig. 6. Experimental L–I–V and WPE characteristics for 100 µm BA laser with a 1500 µm long cavity. The laser device is operated with coated AR of 10% and HR of 99% under 3 A CW at 20°C heatsink temperature. The inset shows the spectrum at 1.5 A CW.

Fig. 7. FFP of simulation and experiment. The dashed line indicates 1/e2 of the peak value.

Fig. 8. (a) Schematic of the low coherence red LD structure; (b) L–I–V curves; (c) the spectrum at 10 A; (d) the FFP at 10 A.

Fig. 9. (a) Schematic of the experimental setup of the speckle measurement; (b) speckle pattern of low coherence red LD structure; (c) speckle pattern of BA laser.