Patent ID: 8731009

Claim:
A supercontinuum light source comprising a pump source arranged to emit pump light in a pump beam, said pump light having a centre wavelength λ centre , the light source further comprising a generator fibre having an input end and an output end, said generator fibre supporting a fundamental mode and one or more higher order modes at least at said centre wavelength, and having a zero dispersion wavelength λ ZDW for said fundamental mode and a transverse refractive index profile with a core region having a characteristic diameter D≦10 μm, said pump source being arranged to inject pump light into the input end of said generator fibre with an optical peak power P≧50 W and a spectral width Δλ spectrum, wherein said generator fibre is a graded index fibre so that said refractive index profile is arranged to allow SRS modal cleaning and λ ZDW −(λ centre +Δλ/2)≧0.