This study focuses on the output characteristics of an 808-nm laser diode (LD) end-pumped Nd∶YVO₄ mode-locked laser with a semiconductor saturable absorber mirror (SESAM). Further, a mode-locked laser with variable output power is designed by the selection of the output mirror transmittance. First, the influence of the output mirror transmittance on the laser mode-locked power and threshold is systematically studied. An output mirror transmittance of 10% and a pumping power of 8 W result in the highest output power of 2.58 W that corresponds to a conversion efficiency of 32.3%, whereas an output mirror transmittance of 0.1% results in a low continuous-wave mode-locked threshold of 1 W and an output power of 0.58 mW. Second, the mode-locked pulse width is measured by using a home-made autocorrelator; the parasitic oscillations of the laser are analyzed based on the autocorrelation traces. Thus, we obtain mode-locked pulses with a pulse width of 13 ps at a repetition rate of 150 MHz by optimizing the output mirror to suppress the parasitic oscillations.