design of 808 nm epitaxial layer structure is demonstrated, and a very low internal loss less than 0.5 cm-1is achieved. the quasi-continuous wave (qcw) high peak power 808 nm laser bar is fabricated with this high efficiency wafer. the bar with a filled factor of 85%, emitter number of 60, emitting width of 140 μm, and cavity length of 2 mm is measured at qcw mode. the peak power is 613 w with a slope efficiency of 1.34 w/a (drive current of 500 a, pulse width of 200 μs, repetition frequency of 400 hz, duty ratio of 8%). the peak wavelength is about 807.46 nm with a spectral half-width full-maximum of 2.88 nm. the lifetime test is also demonstrated at qcw 300 w (8% duty ratio), the lifetime of five bars is all above 3.63×109shot, the current fluctuation is lower than 10% at the constant power of 300 w, which satisfies commercial application requirement. © 2017, chinese lasers press. all right reserved.