Generation and all-optical manipulation of polychromatic photonic molecules
Creators: name: Willms, Stephanie
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität
Year: 2024
Subjects: subject: Nonlinear Optics
subject: Polychromatic Photonic Molecules
subject: Computational Photonics
subject: Optical Solitons
subject: Fiber Optics
subject: Nichtlineare Optik
subject: polychromatische photonische Moleküle
subject: optische Solitonen
subject: Faseroptik
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: The recent demonstration of a novel class of photonic molecules has opened new avenues in the study of soliton bound states, including complex propagation dynamics, tailorable spectral prop- erties, and strong robustness against perturbations. In this work detailed numerical studies of the characteristics, generation options, and suitable system approaches for polychromatic photonic molecules are presented. Photonic molecule states are composed of basically two or more constituents which have to fulfill the prerequisite of group-velocity matching exhibiting different center frequencies located in vastly separated regions of anomalous dispersion. This condition allows the constituent subpulses to engage into a mutual incoherent binding mechanism building up a molecule state. Consequently, the characteristic structure of a photonic molecule is a single localized feature in the time domain and a double-hump structure in the frequency domain. The characteristic double-hump structure in the frequency domain is dictated by the center frequencies of the contributing solitons, while the localized state in the time domain is dressed in interference fringes due to its multi-frequency composition. These states, initially labeled as soliton molecules with two frequencies, have been extended to include additional components, leading to investigations of states with three subpulses or even several equally spaced frequency centers, to which they owe their current designation as polychromatic photonic molecules. The structure of polychromatic photonic molecules is in contrast to the common soliton molecules which obtain a double-hump structure in the time domain, resulting from the phase-related attractive binding between two fundamental solitons. In detail, this work focuses on investigating the properties and inherent dynamics of photonic molecules. The investigations cover basic properties, stability analyses, and diverse scenarios influ- encing spectral and temporal characteristics. The work explores limiting cases where weak energy portions can be transported and transferred in soliton-induced potential wells. Various gener- ation mechanisms are discussed, including direct, radiation-free generation, interaction-induced generation, and self-generation. The influence of input conditions on the creation dynamics is ex- amined, and propagation scenarios are explored aiming to study the impact of the Raman effect, third-order dispersion, and loss on a stable molecule state. External perturbations, induced by dispersive waves and solitons, are considered to assess the robustness of the molecule states and show to initiate a peculiar molecule state transition process. Finally, the concept of polychromatic molecule states is introduced, extending the two-frequency photonic molecule concept to include multiple constituents. The research aims for an integrated approach, focusing explicitly on in- vestigating photonic molecules in a fiber-based setup, where the complex dispersion properties must be intrinsically present. This approach provides flexibility, manageability, and robustness to the system, requiring the appropriate properties for photonic molecule generation. Self-designed and easily manipulable dispersion characteristics of anti-resonant hollow-core fibers are explored, showcasing the versatility of the dispersion properties achievable by altering fiber-specific param- eters. For those fibers also the impact of the nonlinear effect of ionization is investigated