Highly reconfigurable hybrid laser based on an integrated nonlinear waveguide.

Area of Science:

• Optics and Photonics
• Nonlinear Optics
• Laser Physics

Background:

• Traditional passive mode-locking techniques primarily generate Gaussian or hyperbolic secant pulse profiles.
• Controllable generation of versatile pulse shapes from a single laser system remains a significant challenge in ultrafast optics.

Purpose of the Study:

• To demonstrate a single laser system capable of generating multiple, distinct mode-locked pulsing regimes with controllable temporal profiles.
• To investigate the underlying dynamics and develop a theoretical model for versatile pulse shaping in a nonlinear amplifying loop mirror laser.

Main Methods:

• Utilized a nonlinear amplifying loop mirror (NALM) laser incorporating a bandwidth-limiting filter in a nearly dispersion-free configuration.
• Integrated a short nonlinear waveguide to enable distinct control over multiple mode-locked pulsing regimes.
• Developed and applied a compact theoretical model to describe the observed laser dynamics.

Main Results:

• Successfully realized and controlled multiple mode-locked pulsing regimes, including Gaussian pulses, square waves, and fast sinusoidal-like oscillations.
• Achieved variable repetition rates spanning from the fundamental (7.63 MHz) to the 205th harmonic (1.56 GHz).
• Experimentally identified Ikeda instability as the mechanism responsible for square wave generation, differing from previous observations.

Conclusions:

• The presented NALM laser design offers a versatile platform for generating diverse and controllable ultrafast laser pulse shapes.
• The developed theoretical model accurately describes the experimental dynamics, attributing pulse regime control to the interplay between NALM amplification and nonlinearity.
• This approach enables universal laser systems applicable to spectroscopy, ultrafast signal processing, and non-classical light generation.