Generation of 100 nJ pulse, 1 W average power at from an intermode beating mode-locked all-fiber laser

We report on the investigation of intermode beating mode-locked (IBML) pulse generation in a simple all-fiber Tm ³⁺ -doped double clad fiber laser (TDFL). This IBML TDFL is implemented by matching longitudinal-mode frequency between 793 nm laser and TDFL without extra mode locker. The central wavelength of ~1983~nm , the fundamental pulse frequency of ~9.6~MHz and the signal-to-noise ratio (SNR) of >50~dB are achieved in this IBML TDFL. With laser cavity optimization, the IBML TDFL can finally generate an average output power of 1.03 W with corresponding pulse energy of ~107~nJ . These results can provide an easily accessible way to develop compact large-energy, high-power TDFLs.