A Q-switched Thulium-doped Fiber Laser (TDFL) operating at approximately 2 μm wavelength is successfully generated by using four different saturable absorbers (SAs) which are nitrogen-doped graphene in PVA (NG:PVA), nitrogen-doped graphene in PEO (NG:PEO), single-walled carbon nanotube in PVA (SWCNT:PVA), and high pressure carbon monoxide carbon nanotube in PVA (CNTHiPCO:PVA). The SAs integrated in the cavity were able to provide the real saturable absorption in modulating the intra-cavity losses. SWCNT gives the best results with the highest repetition rate and lowest pulse width of 57.45 kHz and 1.958 nJ correspondingly as compared to the other three SAs.