Femtosecond mode-locking and soliton molecule generation based on a GaAs saturable absorber

【摘要】 In the last few years, research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics, Ga As has been used in solidstate and fiber lasers as a mode-locker. However, the pulse widths that have been reported in the searchable published literature are all long and the shortest is tens of picoseconds. Femtosecond pulse widths, desired for a variety of applications,have not yet been reported in Ga As-based pulsed lasers. In this work, we further explore the nonlinear characteristics of Ga As that has been magnetron sputtered onto the surface of a tapered fiber and its application in the generation of femtosecond lasing via effective dispersion optimization and nonlinearity management. With the enhanced interaction between evanescent waves and Ga As nanosheets, mode-locked soliton pulses as short as 830 fs are generated at repetition rates of 4.64 MHz. As far as we know, this is the first time that femtosecond-level pulses have been generated with a Ga As-based saturable absorber. In addition, soliton molecules, including in the dual-pulse state, are also realized under stronger pumping. This work demonstrates that Ga As-based photonic devices have good application prospects in effective polymorphous ultrashort pulsed laser generation.更多还原

【Abstract】 In the last few years, research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics, Ga As has been used in solidstate and fiber lasers as a mode-locker. However, the pulse widths that have been reported in the searchable published literature are all long and the shortest is tens of picoseconds. Femtosecond pulse widths, desired for a variety of applications,have not yet been reported in Ga As-based pulsed lasers. In this work, we further explore the nonlinear characteristics of Ga As that has been magnetron sputtered onto the surface of a tapered fiber and its application in the generation of femtosecond lasing via effective dispersion optimization and nonlinearity management. With the enhanced interaction between evanescent waves and Ga As nanosheets, mode-locked soliton pulses as short as 830 fs are generated at repetition rates of 4.64 MHz. As far as we know, this is the first time that femtosecond-level pulses have been generated with a Ga As-based saturable absorber. In addition, soliton molecules, including in the dual-pulse state, are also realized under stronger pumping. This work demonstrates that Ga As-based photonic devices have good application prospects in effective polymorphous ultrashort pulsed laser generation.更多还原