| Laser-diode pumped all-solid-state pulsed 2?m waveband lasers are becoming more and more popular as a result of their wide applications in the fields of medicine,material processing,research academic,military,and as the role of pumping sources for other mid-infrared lasers.The emergence of new two dimensional(2D)saturable absorber(SA)materials putted the pulsed laser into a new stage.As the most fundamental way for generating ultrafast pulsed lasers,the research on continuous-wave mode-locking(CWML)technique becomes one of the most important fields in 2?m laser field.In this thesis,the experimental studies of Tm3+ and Tm3+/Ho3+ co-doped bulk lasers operating in Q-switching?dual-loss-modulated Q-switching and mode-locking regimes based on different new 2D materials and semiconductor SAs at 2?m waveband were presented.The details of this thesis are as follows:?.Watt-level output from graphene based 2?m wavelength Tm:LuAG laser was demonstrated,with the shortest pulse duration of 235 ns.This is,to the best of our knowledge,the highest output power as well as the shortest pulse duration ever obtained from a graphene mode-locked 2?m waveband lasers.?.By using thermal oxidation decomposition method,WS2 SA was fabricated and characterized in details.The characterization results show that our sample was very suitable to act as a SA.The nonlinear absorption effect of WS2 at 2?m wavelength was announced,and the WS2 based 2?m waveband Tm:LuAG laser was demonstrated.The highest output power and the shortest pulse duration of the WS2 Q-switched Tm:LuAG laser is 1080 mW and 660 ns,respectively.?.By using chemical vapor deposition technique,MoS2 SA was fabricated and characterized.Based on this MoS2 SA,the first 10 W level peak power output was demonstrated in a passively Q-switched 2?m wavelength Tm,Ho:YAP laser.?.The dual-loss-modulated Q-switched 2?m waveband Tm:LuAG laser based on AOM and graphene was demonstrated.Pulses as short as 170 ns and peak power as high as 3117 W were achieved from the dual-loss-modulated laser.Compared with the singly-actively or singly-passively Q-switching operation,the biggest pulse compression ratio and peak power enhancement were 3.11 and 97.4,and the pulse trains from the dual-loss-modulated Q-switching laser was largely enhanced as well.This experimental results indicated that dual-loss-modulation technology could efficiently compress the pulse width,enhance the pulse peak power as well as increase the pulse stability in 2?m wavelength lasers.?.Dual-loss-modulated Q-switched 2?m waveband Tm,Ho:YAP laser based on EOM and GaAs SA was realized for the first time.The shortest pulse width duration of 28 ns as well as the highest peak power of 74 kW were obtained,the biggest pulse compression ratio and peak power enhancement were 8.9 and 500.this is,to the best of our knowledge,the highest peak power ever obtained from Tm-based 2?m waveband lasers.The experimental results shows that dual-loss-modulation technique based on the EOM could efficiently increase the output peak power.? Dual-loss-modulated passively Q-switched 2?m waveband Tm:LuAG laser based on MWCNT and graphene was demonstrated,compared with the singly passively Q-switching operation,the dual-loss-modulated Q-switching laser could compress the pulse width efficiently.We further investigated the mechanics of why dual-loss-modulated passively Q-switching laser could compress the pulse width,and the obtained results of this is not only dual-loss-modulated passively Q-switching provided more losses,but also because the two SAs have different recovery times,they may mainly acting on the rising and falling edge of the pulse.? CWML 2?m wavelength Tm:LuAG laser based on GaSb-SESAM was demonstrated,pulses as short as 13.6 ps was obtained.This is,to the best of our knowledge,the shortest pulse duration obtained from mode-locked 2?m waveband Tm:LuAG laser.The main innovations of this dissertation are as follow:?.Passively Q-switched 2?m waveband Tm:LuAG laser with graphene was demonstrated for the first time,the obtained shortest pulse duration and average output power are 235 ns and 873mW.This is,to the best of our knowledge,the shortest pulse duration and highest average output power that ever obtained from graphene Q-switched 2?m waveband lasers.?.The nonlinear absorption effect of WS2 at 2?m waveband was announced for the first time,and the WS2 based 2 pm waveband Tm:LuAG laser was demonstrated.The highest output power and the shortest pulse duration of the WS2 Q-switched 2?m waveband Tm:LuAG laser is 1080 mW and 660 ns.?.The first 10 W level peak power output from MoS2 Q-switched 2?m waveband laser was demonstrated for the first time,and the obtained shortest pulse duration is 435 ns.?.The dual-loss-modulated Q-switched 2?m waveband Tm:LuAG laser based on AOM and graphene was demonstrated for the first time.Pulses as short as 170 ns and peak power as high as 3117 W were achieved from the dual-loss-modulated laser.?.Dual-loss-modulated Q-switched 2?m waveband Tm,Ho:YAP laser based on EOM and GaAs SA was realized for the first time.The shortest pulse width duration of 28 ns as well as the highest peak power of 74 kW were obtained.? Dual-loss-modulated passively Q-switched 2 pm waveband Tm:LuAG laser based on MWCNT and graphene was demonstrated for the first time,the obtained shortest pulse duration and highest peak power were 102 ns and 171W.We also investigated the mechanics of why dual-loss-modulated passively Q-switching laser could compress the pulse width.? CWML 2?m wavelength Tm:LuAG laser based on GaSb-SESAM was demonstrated for the first time.pulses as short as 13.6 ps was obtained.This is,to the best of our knowledge,the shortest pulse duration ever obtained from mode-locked 2 pm waveband h Tm:LuAG laser. |
PDF Full Text Request