Vortex soliton molecule in a fiber laser.

Area of Science:

• Nonlinear Optics
• Fiber Laser Physics
• Optical Communications

Background:

• Vortex solitons are fundamental nonlinear optical phenomena.
• Passively mode-locked fiber lasers are key platforms for generating ultrashort optical pulses.
• Understanding soliton molecule dynamics is crucial for advanced optical signal processing.

Purpose of the Study:

• To report the generation of vortex soliton molecules (VSMs) in a fiber laser.
• To investigate the dynamics of VSM formation and splitting.
• To explore potential applications in optical communications.

Main Methods:

• Utilizing a passively mode-locked fiber laser.
• Employing a mode selective coupler (MSC) for VSM generation.
• Adjusting the intra-cavity polarization state to control VSM dynamics.

Main Results:

• Successfully generated vortex soliton molecules (VSMs) with variable numbers of molecules.
• Observed ±1-order VSMs.
• Demonstrated VSM splitting into multiple solitons by adjusting polarization.
• Observed variations in soliton number and separation during splitting, with unobservable spectral modulation.

Conclusions:

• VSMs can be generated and controlled in fiber lasers.
• VSM dynamics, including splitting and merging, can be manipulated.
• These findings hold promise for optical communications, particularly in information coding.