Improved spectral flatness and sub-two-cycle pulse generation in octave-spanning Kerr frequency combs using micro-resonators with two zero-dispersion wavelengths

摘要

We show spectral flatness of Kerr frequency combs can be improved with a power fluctuation of <20 dB over one-octave bandwidth, using flattened dispersion profile with two ZDWs. Sub-two-cycle optical pulses (7.5 fs) are generated from the combs.