An optical fiber delivery system for delivering ultrashort optical pulses that can efficiently transmit high peak power, ultrashort optical pulses from an optical pulse source to a desired position in an optical apparatus is provided. An optical system including such an optical fiber delivery system is also provided. The optical fiber delivery system includes light waveguide means 20 for receiving high-peak power, ultrashort optical pulses and transmitting the optical pulses, negative group-velocity dispersion generation means 30 for providing negative group-velocity dispersion to the optical pulses transmitted through the light waveguide means 20, and an optical fiber 40 that transmits the optical pulses transmitted through the negative group-velocity dispersion generation means 30 along a desired distance. The incident ultrashort optical pulses that have been injected into the light waveguide means 20 are converted into down-chirped pulses.