Hollow-core optical fiber based radiation source

A method of generating output radiation, the method comprising:

• selecting one or more parameters of one or more selected from pulsed pump radiation, a hollow core optical fiber comprising a body having a hollow core and a working medium comprised within the hollow core such that the pulsed pump radiation undergoes a soliton self-compression process so as to change a spectrum of the pulsed pump radiation so as to form output radiation,
• generating the pulsed pump radiation for reception by, and propagation through, the hollow core from an input end to an output end;
• and
• applying at least one dispersion control mechanism in a portion of the optical fiber so as to change dispersion characteristics starting at a location, in the portion of the optical fiber, after a point of maximum compression to spectrally shift a dispersive wave generated in the soliton self-compression process, wherein the location is selected so as to attenuate a peak of the dispersive wave to reduce sensitivity of the peak to pulse energy variations.