Readme file for the data submitted towards the paper titled as "Bismuth-doped all-fiber mode-locked laser operating at 1340 nm" The X and Y data of figures.rar file consist of data of plots that are present in the paper titled as above. Fig.1.xlsx (Inset) file containes the data of absorption spectrum of the Bi-doped fiber. Fig.2.xlsx file containes the data of Pulse width variation with pump power of 25 m long Bi-doped fiber for a 1270 nm laser diode pumping. Fig.3.xlsx file contains the data of Pulse train of the ML-BDFL at maximum pump power of 335 mW with a pulse width of 3 ns. Fig.4 (a).xlsx file contains the data of Optical spectrum of the ML-BDFL at a pump power of 335 mW for a 25 m long Bi-doped fiber. Fig.4 (b).xlsx file contains the data of RF spectrum of the ML-BDFL at a pump power of 335 mW for a 25 m long Bi-doped fiber. Fig.6.xlsx file contains the data of Variation of signal power with pump power of the MOPA for a fixed input seed power of 2.5 mW (3.95 dBm). Fig.7.xlsx file contains the data of Signal power variation of the MOPA with seed power for fixed pump power of 420 mW. Fig.8 (a).xlsx file contains the data of Autocorrelation trace of the mode-locked Bi-doped fiber laser. Fig.8 (b).xlsx file contains the data of Sech2 fitting of the autocorrelation trace. Fig.9.xlsx file contains the data of Optical spectrum of the ML-BDFL observed over 2 h of time.