Harnessing a multi-dimensional fibre laser using genetic wavefront shaping

Abstract

The multi-dimensional laser is a fascinating platform not only for the discovery and understanding of new higherdimensional coherent lightwaves but also for the frontier study of the complex three-dimensional (3D) nonlinear dynamics and solitary waves widely involved in physics, chemistry, biology and materials science. Systemically controlling coherent lightwave oscillation in multi-dimensional lasers, however, is challenging and has largely been unexplored; yet, it is crucial for both designing 3D coherent light fields and unveiling any underlying nonlinear complexities. Here, for the first time, we genetically harness a multi-dimensional fibre laser using intracavity wavefront shaping technology such that versatile lasing characteristics can be manipulated. We demonstrate that the output power, mode profile, optical spectrum and mode-locking operation can be genetically optimized by appropriately designing the objective function of the genetic algorithm. It is anticipated that this genetic and systematic intracavity control technology for multi-dimensional lasers will be an important step for obtaining high-performance 3D lasing and presents many possibilities for exploring multi-dimensional nonlinear dynamics and solitary waves that may enable new applications.

On-demand harnessing of photonic soliton molecules

“…The ability to tune the wavelength is needed in many applications, including optical sensing, metrology, and spectroscopy [34,62]. The usual tuning methods employ the nonlinear wave mixing [63], or the use of high-speed electric optical modulators.…”

“…The method works via controlling the complex dispersion: its real part determines the balance between the GVD and nonlinearity in the mode-locked laser, while the imaginary (dispersion-loss) part maintains the compensation of the frequency-dependent losses by the gain. Studies of manipulations of the dispersion had a long history in the course of the development of the dispersion management for mode-locked lasers [29][30][31][32][33][34]. In particular, a fourth-order soliton was recently created by engineering both second-and fourth-order GVD in a mode-locked laser system [32].…”

Anti-scattering light focusing by fast wavefront shaping based on multi-pixel encoded digital-micromirror device

“…As photons are propagating through a scattering medium, their trajectories are randomly changed, so they cannot be focused to a micrometer-scale spot, which fundamentally limits the application of optical imaging, photon therapy, and optogenetics 1,2 . By using a spatial light modulator (SLM), wavefront shaping (WS) can manipulate the incident wavefront so that the scattered photons will contribute a constructive interference and form a tight focus against the scattering medium 3,4 . The applications of WS include improving the spatial resolution of biomedical imaging 5,6 , optogenetics 7 , and cataract correction 8 , as well as enlarging the viewing angle in dynamic three-dimensional holography 9 .…”

Intelligent Breathing Soliton Generation in Ultrafast Fiber Lasers

“…[30,31] The application of advanced algorithmic tools and adaptive feedback and control has recently greatly boosted the progress in the search for a truly selfoptimising laser, and a number of groups have reported on different approaches to automate optimisation of one or more parameters of the laser cavity to reach and maintain a desired operating state. [32][33][34][35][36][37][38][39][40][41] A recent work [42] introduced extra novelty by incorporating fast spectral measurements into the feedback loop of the laser setting which, along with an intelligent polarisation search algorithm, enabled real-time control of the spectral width and shape of ultrashort mode-locked pulses. Despite these significant advances, the intelligent generation of breathing solitons in a fibre laser remains challenging because breathers refer to a highly dynamical state in which the pulse spectral and temporal characteristics change drastically within a period of oscillation, while existing machine-learning strategies are mostly designed to target laser generation regimes of parameter-invariant, stationary pulses.…”