The single emitter and bars of 780 nm semiconductor laser have been designed and fabricated. The epitaxial layers were prepared by the metal organic chemical vapor deposition technology. GaAsP and GaInP were used as the quantum well and waveguide layer, respectively. The confinement layers were AlGaInP material with low refractive index. The bandgap between the quantum well and the waveguide layer was 0.15 eV, while the bandgap between the waveguide layer and the confinement layer was 0.28 eV. The high bandgap was effective in suppressing carrier leakage. The 1.55 μm thick large optical cavity epitaxy structure increases the beam’s size and alleviates the cavity optical surface damage problem. The asymmetric structure suppresses high-order fast axis modes. Using the ultra-high vacuum cleavage and passivation technology, an amorphous ZnSe passivation layer was deposited on the laser cavity facets. The ZnSe passivated single emitter device with 150 μm width and 4 mm cavity length, did not show COD phenomenon with 16.3 W continuous-wave output, when the current was 15 A. In this case, the slope efficiency reached 1.27 W/A while the electro-optic conversion efficiency was 58%, and the divergence angle of slow-axis was 9.9° and the spectral width was 1.81 nm. The 1-cm laser bar with lateral emitter fill factor of 40%, reached continuous-wave 180 W output power at 192 A, and the electro-optic conversion efficiency was 50.7%, the spectral width was 2.2 nm.