We demonstrate the generation of 2.5-ps pulses by a Fabry-Perot semiconductor laser with 15-nm wavelength tunability. A commercial laser is switched to single longitudinal mode pulse emission by self-seeding, using an external grating. The sidemode suppression ratio is better than 15 dB, with a peak value of 21 dB. The linearly red chirped pulses are compressed from 21-30 ps to 2.5-3.5 ps in a dispersion-shifted fiber. The simple experimental setup consists of a fiber coupler, a grating, and the dispersion-shifted fiber.