Observation of 550 MHz passively harmonic mode-locked pulses at L-band in an Er-doped fiber laser using carbon nanotubes film

Huang Qianqian¹, Zou Chuanhang¹, Wang Tianxing^{1, 5}, Araimi Mohammed Al^{2, 3, 4}, Rozhin Aleksey^{2, 3}, Mou Chengbo^{1, †}

(color online) (a) The observed pulse train of 550 MHz pulses (insert: the left one is optical spectrum, the right one is the pulse train spanning 0.2 μs), (b) measured RF spectra at 550 MHz (inset: RF spectrum centered in 550 MHz), and (c) harmonic order versus the given pump power.