Kelly sidebands suppression and wavelength tuning of conventional soliton in a Tm-doped hybrid mode-locked fiber laser with all-fiber Lyot filter

We demonstrate a stable conventional soliton in a Tm-doped hybrid mode-locked fiber laser by employing a home-made all-fiber Lyot-filter (AFLF) and a single-wall carbon nanotube (SWCNT). The AFLF, designed by sandwiching a piece of polarization maintained fiber (PMF) with two 45° tilted fiber gratings (45°-TFGs) which inscribed by a UV laser in PMF with phase-mask scanning technique, shows large filter depth of ~9 dB and small insertion loss of ~0.8dB. By optimizing the free spectral range (FSR) of the AFLF, the Kelly sidebands of conventional soliton centered at 1966.4 nm can be dramatically suppressed without impairing the main shape of soliton spectrum. It gives the pulse duration of 1.18ps and bandwidth of 3.8 nm. By adjusting the temperature of the PM fiber of the AFLF from 7 °C to 60 °C, wavelength tunable soliton pulses ranging from 1971.62 nm to 1952.63 nm are also obtained. The generated soliton pulses can be precisely tuned between 1971.62 nm and 1952.63 nm by controlling the temperature of the AFLF.