High power high beam quality 1060-nm InGaAs/GaAs quantum well (QW) semiconductor laser diode with an asymmetric large optical cavity (LOC) is designed and fabricated. The laser diode consists of compressively strained double InGaAs/GaAs quantum wells and a GaAs/AlGaAs separate confinement structure. To improve the high power performance, the transversal optical cavity is optimized to have low fast axis far-field divergence angle, large optical spot size and low facet optical density, low internal optical absorption loss and high internal quantum efficiency. By employing a weak optical confinement Al0.1Ga0.9As waveguide with thickness of 4 μm, a low transversal far-field divergence angle of 20° and large optical spot size near 1 μm are obtained. By detuning the QW position, the asymmetric waveguide with thinner p-side waveguide enables the laser diode high internal quantum efficiency even in high current injection level. Based on the optimization, 1.3 W continue wave optical power is achieved for broad area lasers with cavity length and strip width of 2 mm and 50 μm, respectively. For single spatial mode ridge waveguide laser diodes with same cavity length, 600 mW continue wave optical power is obtained at 10 ℃.