By replacing a semiconductor saturable absorber mirror (SESAM) made up of iron doped InGaAs/InP multiple quantum wells (MQW) (Gicquie-Guezo, 2004) by a saturable absorber incorporating nanotubes (SAINT) (Set, 2004) we have drastically decreased the noise level as well as improved the output pulse characteristics delivered by a passively mode-locked Er3+-doped fiber oscillator. Our laser consists of 235 cm-long, highly erbium-doped fiber core-pumped by a single-mode laser diode (120 mw max. power) and pieces of standard telecom fibers . A free space segment settles the cavity in order to manage beam focusing on the SA either constituted of SESAM or SAINT. The latter is made up of SW-CNT obtained by laser ablation of a doped graphitic target.