Fig. 1. Transverse modes (a) and electron leakage (b) in the reference structure

Fig. 2. Power efficiency of the reference structure with different p-waveguide doping

Fig. 3. Transverse modes in the SLOC with mode control layers

Fig. 4. (a) Transverse modes in the SLOC with grading p- waveguide, (b) electron concentration comparision with and without grading-waveguide

Fig. 5. Slope efficiency (a) and voltage (b) comparison of the grading and reference structures

Fig. 6. Power efficiency (a) and vertical far-field (b) of the grading and reference structures

Fig. 7. Calculated temperature dependence of slope efficiency and threshold comparison of the grading and reference structures，the slope efficiency values are extracted from the output power at 10 A to 20 A

Fig. 8. Calculated power (a) and gain (b) distribution in the cavity with uniform current injection

Fig. 9. Conception of linear current (a), and calculated power and gain distribution (b) in the cavity with linear current injection

Fig. 10. Carrier density (a) and output power at 20 A (b) comparison of linear and uniform current injection

Fig. 11. Designed output power and efficiency of the 4-mm-long and 100 μm wide broad-area laser diode