We experimentally demonstrate the operation of a laser based on self-phase modulation followed by offset spectral
filtering. This laser has three operation modes: a continuous-wave mode, a self-pulsating mode where the laser self
ignites and produces pulses, and a pulse-buffering mode where no new pulse is formed from spontaneous emission noise
but only pulses already propagating or pulses injected in the laser cavity can be sustained. In the self-pulsating and
pulse-buffering modes, the laser is multi-wavelength and continuously tunable over the entire gain band of the
amplifiers. The output pulse width is quasi transform-limited with respect to the spectral-width of the filters used in the
cavity. Overall, this device provides a simple alternative to pulsed laser source and also represents a promising approach
for signal buffering.