Underlying nonlinear science of hybrid SOA-fiber laser systems with feedback

• Applicant: Dr. Andrei Vladimirov
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 445430311

• Final Report Year: 2024

Final Report Abstract

We have studied complex nonlinear dynamical regimes in hybrid SOA fiber lasers, with particular emphasis on coherent structures and short pulse generation. The study included various laser configurations, such as nonlinear mirror mode-locked lasers, dual spectral filter laser systems, Fourier domain mode-locked (ML) lasers, long cavity lasers, and others, which were analyzed both numerically and analytically. A large part of our efforts has been focused on the development of models for SOA fiber lasers. We have developed and explored a delay differential equation (DDE) model for a nonlin­ ear optical/amplifying mirror ML laser. Simulation results revealed large windows of regular and irregular ML single and multipulse regimes. lt was found that lasers with asymmetric beam splitters can induce regular ML regimes, even when the laser-off solution is unstable. An important result obtained is that a slow relaxation of gain inversion can prevent flip instabilities and the formation of square wave patterns in laser output. Further, the dynamics of a nonlinear cavity with two spectral filter was explored, although the lack of experimental data hindered further investigation on Mamyshev oscillators and lasers with electronic feedback. Analytical and numerical studies were conducted on the interaction dynamics of short optical pulses in fiber and semiconductor lasers. Asymptotic equations governing the evolution of pulse separations and phases were derived and analyzed, revealing various pulse interactions and regimes. Equations for locally and non-locally interacting pulses were developed within the framework of DDE ML laser models. Efforts were applied to refine mean-field ML laser models. This included developing a generalized version of the Haus model that can capture Q-switched ML behavior, leading-edge instabilities, and harmonic ML regimes. The project has also addressed the incorporation of chromatic dispersion into DDE laser models, proposing novel approaches to model nonlinear cavity dynamics and SOA-fiber lasers, in particular the approach based on the application of neutral DDEs. These models effectively described various dynamical regimes observed experimentally. Linear stability analysis and simulations demonstrated that strong anomalous dispersion can induce modulational instability in long cavity SOA-fiber lasers, leading to turbulent output. Transition from thermal to Poisson statistics and the emergence of coherent structures triggering turbulent behavior within the laser system were also studied. Overall, the project provided deeper insights into the dynamics of hybrid SOA-fiber lasers and offered avenues for advancing their performance and functionality.

Publications

• Delay-differential-equation model for mode-locked lasers based on nonlinear optical and amplifying loop mirrors. Physical Review A, 104(3).
  Vladimirov, A. G.; Suchkov, S.; Huyet, G. & Turitsyn, S. K.
  
• Dissipative soliton interaction in Kerr resonators with high-order dispersion. Physical Review A, 103(6).
  Vladimirov, A. G.; Tlidi, M. & Taki, M.
  
• Generalized Haus master equation model for mode-locked class- B lasers. Physical Review E, 104(1).
  Nizette, Michel & Vladimirov, Andrei G.
  
• Nonlinear dynamical properties of frequency swept fiber-based semiconductor lasers. Journal of Physics: Photonics, 3(4), 044002.
  Slepneva, Svetlana & Pimenov, Alexander
  
• Short- and long-range temporal cavity soliton interaction in delay models of mode-locked lasers. Physical Review E, 105(4).
  Vladimirov, Andrei G.
  
• Temporal Solitons in an Optically Injected Kerr Cavity with Two Spectral Filters. Optics, 3(4), 364-383.
  Pimenov, Alexander & Vladimirov, Andrei G.
  
• Decoherence and Turbulence Sources in a Long Laser. Physical Review Letters, 131(5).
  Roche, Amy; Slepneva, Svetlana; Kovalev, Anton; Pimenov, Alexander; Vladimirov, Andrei G.; Giudici, Massimo; Marconi, Mathias & Huyet, Guillaume
  
• Temporal Cavity Soliton Interaction in Passively Mode-Locked Semiconductor Lasers. Optics, 4(3), 433-446.
  Vladimirov, Andrei G.
  
• Neutral delay differential equation model of an optically injected Kerr cavity. Physical Review E, 109(2).
  Vladimirov, Andrei G. & Dolinina, Daria A.