Breathing Dissipative Soliton Molecule Switching in a Bidirectional Mode‐Locked Fiber Laser

Abstract

Breathing optical solitons propagating in a dissipative nonlinear system can interact and bind stably, forming an optical soliton molecule that presents striking molecule‐like dynamics. To date, the breathing soliton pair has been mainly observed in the microcavity platform, and the peculiar dynamic evolution of breathing soliton molecules (BSMs) remains largely unexplored in mode‐locked fiber lasers. Herein, the transient switching dynamics of BSMs in a bidirectional ultrafast fiber laser is revealed, specifically triggered at different parameter spaces of saturable absorption with manipulation polarizations that maintain constant pulse separation or undergo strong repulsion and kink after switching. All‐optical switching of breather molecules and significantly increasing multiple soliton molecules’ switching of two or three solitons between states with different binding separations by applying a strong stimulus with periodic pump modulation is demonstrated. The instantaneous pulse breakup can be induced by the collision of bidirectional breathing solitons in each switching, which is characteristic of the breathing solitons in a bidirectional fiber laser and further corroborated by numerical simulation. The study unveils new perspectives into the ultrafast transient process of BSMs in various dissipative systems.

Single-cavity dual-comb fiber lasers and their applications

“…An all-fiber bidirectional mode-locked laser based on carbon nanotube saturable absorber was realized by removing the intracavity optical isolator [23]. Later on, simultaneous modelocking in the clockwise and counterclockwise directions in the ring cavity has become the common implementation of the bidirectional lasing [23,30,[66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84]. Furthermore, in order to avoid the effects of competition between bidirectional pulses, there are also a variety of bidirectional fiber laser structures that share only part of the optical cavity [79, [83][84][85][86].…”

Real‐Time Investigation of Ultrafast Dynamics through Time‐Stretched Dispersive Fourier Transform in Mode‐Locked Fiber Lasers

“…[90] When the intensities of these subordinate peaks achieve the threshold values, annihilation of subordinate pulses happens, leaving behind the dominant soliton pulse oscillating in the laser cavity, thus completing the entire process and achieving stable MLFL. The bidirectional MLFL in the DS regime was also employed for the investigation of complex motion dynamics in the MLFL, i.e., soliton breathing [91,92] and soliton explosion [84] in the next section.…”

“…[116] The breathing ratio is defined as the ratio between the largest to the narrowest spectrum within a period. [91] The formation of a stationary DS is denoted by the breathing ratio of 1. [18] By increasing the pump power, the breathing ratios decreased from 1.35, 1.05 to ≈1 in Figure 14a,d,g, respectively.…”

Phase-tailored assembly and encoding of dissipative soliton molecules

“…The on-going discovered internal molecular dynamics, via using the advanced spectral observations, in essence can enrich the manipulation mechanism on soliton molecules [33][34][35][36][37][38][39] . Intrinsic insights into the mutual interactions reveal the scenarios of gaingoverned energy flow within the binding structures, which emphasizes the inevitable routes to the controllable assembly of the molecular patterns.…”