Disclosed is a burst mode oscillation method for burst mode oscillation by controlling the peak output of light pulses in a laser system. The burst mode oscillation apparatus includes a seed beam generator which receives electrical input signals having different pulse widths, modulates pulse widths and amplitudes of outputs in output light according to the received electrical input signals, and outputs the modulated pulse light, an amplifier which amplifies the modulated pulse light and outputs amplified pulse light, and a non-linear wavelength converter which can control wavelength-converted output light according to the amplitudes of the peak output changed through the pulse widths of the amplified pulse light.