  Phase noise is very important for the ultrafast pulse application in
telecommunication, ultrafast diagnose, material science, and biology. In this
paper, two types of carbon nano-materials, single-wall carbon nanotube and
graphene oxide, are investigated for noise suppression in ultrafast photonics.
Various properties of the wall-paper SAs, such as saturable intensity, optical
absorption and degree of purity, are found to be key factors determining the
phase noise of the ultrafast pulses. A reduced-noise femtosecond fiber laser is
experimentally demonstrated by optimizing the above parameters of carbon
material based SAs. The phase noise reduction more than 10 dB at 10 kHz can be
obtained in the experiments. To our knowledge, this is the first time that the
relationship between different carbon material based SAs and the phase noise of
mode-locked lasers has been investigated. This work will pave the way to get a
high-quality ultrashort pulse in passively mode-locked fiber lasers.
