Pulse buildup dynamics in a self-starting Mamyshev oscillator

Area of Science:

• Nonlinear Optics
• Ultrafast Laser Technology
• Fiber Laser Physics

Background:

• Mamyshev oscillators (MOs) generate high-performance pulses but often lack self-starting capabilities due to non-resonant cavities.
• Pulse buildup dynamics in MOs remain largely unexplored.
• Investigating self-starting mechanisms is crucial for advancing MO applications.

Purpose of the Study:

• To investigate the dynamics of single-pulse (SP) and multi-pulse formation in a self-starting MO.
• To explore the influence of oscillator parameters, pump power, and polarization states on pulse formation.
• To differentiate MO pulse dynamics from conventional passive mode-locked fiber lasers (CPMLFLs).

Main Methods:

• Experimental investigation of a self-starting Mamyshev oscillator.
• Systematic adjustment of oscillator parameters, pump power, and polarization states.
• Analysis of pulse dynamics, including single-pulse (SP) and multi-pulse formation, bound state pulses (BSPs), pulse bunch, and harmonic mode-locked pulses (HMLPs).

Main Results:

• Achieved self-starting capabilities for both single-pulse (SP) and multi-pulse regimes by adjusting oscillator parameters.
• Demonstrated that increasing pump power in SP self-starting leads to bound state pulses (BSPs) with an increasing pulse number.
• Observed distinct pulse dynamics compared to CPMLFLs, where BSPs formed via noise amplification and bounding.
• Identified conditions for obtaining BSPs, pulse bunch, and harmonic mode-locked pulses (HMLPs) through multi-pulse self-initiation by tuning polarization and pump power.
• Confirmed that original states can be recovered by increasing pump power from zero, maintaining oscillator polarization and filter interval, similar to CPMLFLs.

Conclusions:

• Self-starting Mamyshev oscillators exhibit controllable single and multi-pulse dynamics.
• The formation of bound state pulses in MOs differs from conventional fiber lasers.
• These findings provide critical insights into MO pulse dynamics, essential for ultrafast laser technology and nonlinear optics research.