Formation of optical supramolecular structures in a fibre laser by tailoring long-range soliton interactions

Abstract

Self-assembly of fundamental elements through weak, long-range interactions plays a central role in both supramolecular DNA assembly and bottom-up synthesis of nanostructures. Optical solitons, analogous in many ways to particles, arise from the balance between nonlinearity and dispersion and have been studied in numerous optical systems. Although both short- and long-range interactions between optical solitons have attracted extensive interest for decades, stable soliton supramolecules, with multiple aspects of complexity and flexibility, have thus far escaped experimental observation due to the absence of techniques for enhancing and controlling the long-range inter-soliton forces. Here we report that long-range soliton interactions originating from optoacoustic effects and dispersive-wave radiations can be precisely tailored in a fibre laser cavity, enabling self-assembly of large numbers of optical solitons into highly-ordered supramolecular structures. We demonstrate several features of such optical structures, highlighting their potential applications in optical information storage and ultrafast laser-field manipulation.

Collective synthesis and dissociation of soliton molecules in parallel optical-soliton reactors

“…The optically-driven acoustic vibration in the PCF core divides the ~ 20 m cavity (~ 104 ns round-trip time) into 195 time-slots ~ 532 ps wide (one acoustic cycle), creating a self-organized and self-stabilized optomechanical lattice 14 . At pump powers above 600 mW, this lattice can be adjusted to host a variety of solitonic supramolecules 15 . Each time-slot of the optomechanical lattice, functioning as a potential well, can stably trap one or more solitons bound by long-range and/or short-range forces (see Fig.…”

“…Long-range bound, phase-uncorrelated soliton states 15 are ideal start-and end-points for the synthesis and dissociation of phase-locked soliton molecules. In order to initiate soliton reactions, long-range repulsive forces between solitons must be controlled either globally or individually.…”

“…The studies on soliton interactions continue to date and are currently experiencing a vibrant renaissance, partly due to developments of the timestretched dispersive Fourier transform (DFT) method 6 which facilitates resolving of transient soliton dynamics, as well as due to trending focuses on soliton microresonators [7][8][9] which, as novel platforms, advance rapidly toward chip-scale integration. In parallel, many light-matter analogies have been suggested for multi-soliton complexes bound by soliton interactions [10][11][12][13][14][15][16] , epitomized by the "soliton molecules" 17,18 which refers to closely bound solitons through direct interactions [19][20][21][22] . Reminiscent of chemical molecules synthesized from single atoms, optical soliton molecules behave like a single entity while displaying complex internal dynamics 11,12,23−26 , and have attracted considerable interest both in fundamental nonlinear physics and refreshed application promises such as ultrafast lasers 10,27,28 , spectroscopy 29 ,optical communications 2,30 and all-optical information processing 3,12,14,31 .…”

“…These solitons are actually results of double balances, with gain and loss in addition to nonlinearity and dispersion, known as dissipative solitons 10 . To understand the stochasticity of their complex interactions 24,32,35−37 in the nonlinear dissipative system from a collective level, large numbers of solitons and soliton complexes with controllable interactions are demanded, which, however, has long been challenging in the experiments 12,14,15 . In particular, as analogous with chemical reactions between atoms, the synthesis of soliton-molecules from single solitons, and their dissociation into single solitons 10 has not yet been experimentally demonstrated in a fully controlled manner so far.…”

“…Several solitonic elements can be temporally isolated and stably trapped within each time-slot of the optomechanical lattice, forming a stable supramolecular structure 15 . In this work we report that the consecutive time-slots of the optomechanical lattice can function as parallel soliton "reactors" which can be controlled with all-optical techniques, echoing experiments on controlling chemical reactions by atomic manipulation 44 .…”