Fig. 1. Tm, Ho:LLF laser experimental device using graphene oxide as a saturable absorber

Fig. 2. Relationship between continuous optical output power and pump power

Fig. 3. Relationship between the best transmittance of the resonant cavity and the pump power

Fig. 4. Q-switched pulse repetition rate and pulse duration versus the absorbed pump power

Fig. 5. After adding GO-SA, Tm, Ho: LLF laser output power changes with pump power

Fig. 6. Mode-locked spectrogram

Fig. 7. Mode-locked pulse trains