Dynamics of a class-A nonlinear mirror mode-locked laser

Area of Science:

• Nonlinear optics
• Theoretical physics
• Laser dynamics

Background:

• Class-A ring lasers are fundamental optical systems.
• Nonlinear amplifying loop mirrors introduce complex dynamics.
• Understanding pulse formation is crucial for laser applications.

Purpose of the Study:

• To theoretically investigate the dynamics of a unidirectional class-A ring laser.
• To analyze instabilities leading to square-wave and pulse generation.
• To characterize the properties of mode-locked pulses and their interactions.

Main Methods:

• Utilizing a delay differential equation model.
• Performing linear stability analysis in the large delay limit.
• Investigating the formation and interaction of square waves and pulses.

Main Results:

• Continuous-wave regimes destabilize via modulational, Turing-type, and square-wave instabilities.
• Mode-locked pulses exhibit asymmetric shapes with distinct trailing and leading edge decay rates.
• Asymmetric pulse interactions lead to the formation of harmonic mode-locked regimes.

Conclusions:

• The study elucidates the mechanisms behind square-wave and mode-locked pulse formation in ring lasers.
• Asymmetric pulse dynamics are key to understanding harmonic mode-locking.
• Theoretical insights provide a foundation for controlling laser output characteristics.