Generation of noise-like rectangular pulse was investigated systematically in an Er–Yb co-doped fiber laser based on an intra-cavity coupler with different coupling ratios.When the coupling ratio was 5/95,stable mode...Generation of noise-like rectangular pulse was investigated systematically in an Er–Yb co-doped fiber laser based on an intra-cavity coupler with different coupling ratios.When the coupling ratio was 5/95,stable mode-locked pulses could be obtained with the pulse packet duration tunable from 4.86 ns to 80 ns.The repetition frequency was 1.186 MHz with the output spectrum centered at 1.6μm.The average output power and single pulse energy reached a record 1.43 W and1.21μJ,respectively.Pulse characteristics under different coupling ratios(5/95,10/90,20/80,30/70,40/60)were also presented and discussed.展开更多
To overcome Yb lasing,a kilowatt-level 1535 nm fiber laser is utilized to in-band pump an Er:Yb co-doped fiber(EYDF)amplifier.The output power of a 301 W narrow-linewidth EYDF amplifier operating at 1585 nm,with 3 dB ...To overcome Yb lasing,a kilowatt-level 1535 nm fiber laser is utilized to in-band pump an Er:Yb co-doped fiber(EYDF)amplifier.The output power of a 301 W narrow-linewidth EYDF amplifier operating at 1585 nm,with 3 dB bandwidth of 150 pm and M^(2)<1.4,is experimentally demonstrated.To the best of our knowledge,it is the highest output power achieved in L-band narrow-linewidth fiber amplifiers with good beam quality.Theoretically,a new ion transition behavior among energy levels for in-band pumping EYDF is uncovered,and a spatial-mode-resolved nonlinearityassisted theoretical model is developed to understand its internal dynamics.Numerical simulations reveal that the reduction in slope efficiency is significantly related to excited-state absorption(ESA).ESA has a nonlinear hindering effect on power scaling.It can drastically lower the pump absorption and slope efficiency with increasing pump power for in-band pumped EYDF amplifiers.Meanwhile,optimized approaches are proposed to improve its power to the kilowatt level via in-band pumping.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61435009,61235008,and 61405254)
文摘Generation of noise-like rectangular pulse was investigated systematically in an Er–Yb co-doped fiber laser based on an intra-cavity coupler with different coupling ratios.When the coupling ratio was 5/95,stable mode-locked pulses could be obtained with the pulse packet duration tunable from 4.86 ns to 80 ns.The repetition frequency was 1.186 MHz with the output spectrum centered at 1.6μm.The average output power and single pulse energy reached a record 1.43 W and1.21μJ,respectively.Pulse characteristics under different coupling ratios(5/95,10/90,20/80,30/70,40/60)were also presented and discussed.
基金supported by the National Natural Science Foundation of China(Nos.62122040,62075113 and 61875103)。
文摘To overcome Yb lasing,a kilowatt-level 1535 nm fiber laser is utilized to in-band pump an Er:Yb co-doped fiber(EYDF)amplifier.The output power of a 301 W narrow-linewidth EYDF amplifier operating at 1585 nm,with 3 dB bandwidth of 150 pm and M^(2)<1.4,is experimentally demonstrated.To the best of our knowledge,it is the highest output power achieved in L-band narrow-linewidth fiber amplifiers with good beam quality.Theoretically,a new ion transition behavior among energy levels for in-band pumping EYDF is uncovered,and a spatial-mode-resolved nonlinearityassisted theoretical model is developed to understand its internal dynamics.Numerical simulations reveal that the reduction in slope efficiency is significantly related to excited-state absorption(ESA).ESA has a nonlinear hindering effect on power scaling.It can drastically lower the pump absorption and slope efficiency with increasing pump power for in-band pumped EYDF amplifiers.Meanwhile,optimized approaches are proposed to improve its power to the kilowatt level via in-band pumping.
