Real-time observation of dissipative optical soliton molecular motions (1702.01161v1)

Abstract: Real-time access to the internal ultrafast dynamics of complex dissipative optical systems opens new explorations of pulse-pulse interactions and dynamic patterns. We present the first direct experimental evidence of the internal motion of a dissipative optical soliton molecule generated in a passively modelocked erbium-doped fiber laser. We map the internal motions of a soliton pair molecule by using a dispersive Fourier-transform imaging technique, revealing different categories of internal pulsations, including vibration-like and phase drifting dynamics. Our experiments agree well with numerical predictions and bring insights to the analogy between self-organized states of lights and states of the matter.

• The paper demonstrates that real-time DFT imaging can reveal both vibrational and sliding phase dynamics within dissipative optical soliton pairs.
• The research confirms experimental observations with numerical simulations, substantiating energy exchanges and phase evolution in soliton molecules.
• The findings suggest practical applications in improving optical communication and pulse shaping through enhanced control of soliton interactions.

Real-Time Observation of Dissipative Optical Soliton Molecular Motions

The paper presents a significant investigation into the real-time observation of internal motions within dissipative optical soliton molecules, facilitated by using a dispersive Fourier-transform (DFT) imaging technique. It is essential to appreciate the soliton concept's versatility, which finds applications across various domains of nonlinear science, including fluid dynamics, biology, plasma physics, and photonics. With advancements in optical materials and laser technologies, the paper of solitons in nonlinear optics has garnered continuous interest, not just for theoretical exploration but also for practical applications in designing stable pulse sources.

Dissipative solitons, a class within this field, surface in propagation media encompassing both gain and loss. They are defined by their balance of an electromagnetic field through energy exchanges with the environment influenced by nonlinearity, dispersion, and diffraction. When multiple dissipative solitons coexist in a laser cavity, they interact through various mechanisms that can lead to the formation of stable multisoliton bound states, referred to as soliton molecules. These interactions and formations bear intriguing similarities to states of matter, promoting self-assembly into stable entities.

The current research focuses on mapping the dynamics within soliton pairs generated in an erbium-doped fiber laser. By employing the DFT technique, this paper successfully visualizes and categorizes different types of internal pulsations. Among these, notable dynamics include vibration-like behaviors and phase drifting, both clearly substantiated by experimental data and numerical predictions.

Key Findings and Numerical Confirmation

One of the primary achievements of this research is the empirical evidence establishing the presence of internal motion within soliton pair molecules. The application of the DFT measurement technique provided real-time spectral analysis, unveiling the evolutions of the relative phase and temporal separations between solitons. The experiments identified two main classes of soliton molecular dynamics:

1. Vibrational Dynamics: Evidencing a combined oscillation in both the relative phase and temporal separation, resembling the molecular vibrations seen in physical matter.
2. Sliding Phase Dynamics: Characterized predominantly by a sliding phase without significant change in temporal separation, this behavior highlights a peculiar feature unique to optical soliton molecules not paralleled in matter molecules.

These experimental observations were corroborated by numerical simulations, aligning well with theoretical predictions and demonstrating energy exchanges within the soliton pairs as a salient characteristic. The numerical analysis offered additional insights into the phase dynamics and the energies of the individual solitons, albeit currently beyond the reach of present measurement technique precision.

Implications and Future Directions

The paper provides definitive real-time evidence of soliton molecular motions, a previously unresolved facet. This advancement not only enriches the understanding of soliton interactions in dissipative systems but also strengthens the analogical framework linking optical phenomena to molecular dynamics in physical substances. In application, these findings hold potential in advancing robust optical communication techniques and enhancing the multi-level encoding capabilities of light pulses.

Moving forward, these insights into the dynamic structuring of dissipative optical systems could stimulate further research into the self-organization of molecules and the autonomous assembly of soliton-based systems. Additionally, overcoming current technical limitations in measurement precision could pave the way for deeper exploration into energy dynamics within these structures.

In conclusion, this paper has undeniably expanded the comprehension of complex ultrafast dynamics of soliton molecules, laying groundwork for subsequent advancements in both theoretical frameworks and practical applications within optical sciences.