Photobleaching of fiber bragg gratings written through the fiber coating

A method for providing a low absorption Bragg grating along a grating region of an optical fiber, comprising:

• a) writing the Bragg grating along the grating region by multiphoton absorption of ultrafast light pulses impinged on said grating region, said ultrafast light pulses also inducing defects in the grating region;
• and
• b) photobleaching the Bragg grating by propagating a photobleaching light beam along the optical fiber for a sequence of time periods each associated with a different optical power level, the photobleaching light beam interacting with the grating region so as to reduce the defects induced by the ultrafast light pulses in a substantially non-thermal regime.