A supercontinuum light source can include a seed laser arranged to provide seed pulses with a pulse frequency Fseed; a pulse frequency multiplier (PFM) arranged to multiply the seed pulses by converting pulses having the pulse frequency Fseed to pump pulses with a pulse frequency Fpump, where Fpump is larger than Fseed; and a non-linear element arranged to receive said pump pulses and convert said pump pulses to pulses of supercontinuum light. The PFM can further include a splitter for splitting pulses into first and second sub beams each having the same pulse frequency, where the PFM is configured such that the sub beams experience different delays; and a combiner for combining said first and second sub beams into a beam having the pulse frequency that is greater than said same pulse frequency. The splitter can have an uneven splitter ratio.