Highly strained InGaAs ridge waveguide lasers were fabricated with pulsed anodic oxidation. The laser structure was grown by molecular beam epitaxy (MBE) system. The output powers up to 50 mW per facet in CW mode were reached at room temperature for the 4 μm stripe lasers. The threshold current density of 300 A/cm2 was achieved with 600 μm cavity length. The emission wavelength at 100 mA was 1.19 μm. The slope efficiency was 0.45 W/A in linear output region of light-current characteristics. The laser characteristic temperature was 129 K (20℃―100℃).