We propose and demonstrate a passively harmonic mode-locked erbium-doped fiber laser (EDFL) using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film. The laser allows generation of the pulses with a repetition rate of 580 MHz, which corresponds to the 22nd harmonics of a 26.3 MHz fundamental repetition rate under 323 mW pump power. A particularly noteworthy feature of the pulses is the super-mode suppression ratio (SMSR), which is over 40 dB, indicating a stable operation.
