Manipulation of strongly interacting solitons in optical fiber experiments

TL;DR

This paper advances the manipulation of complex optical soliton interactions in fibers by developing eigenvalue response functions within the inverse scattering transform framework, supported by experiments demonstrating precise control over soliton characteristics.

Contribution

It introduces eigenvalue response functions for soliton manipulation in optical fibers, enabling control even during strong overlaps, and validates this approach experimentally.

Findings

Response functions allow manipulation of soliton velocities and amplitudes.

Experimental setup confirms theoretical predictions of soliton detachment.

Robust control of solitons demonstrated in long-distance fiber experiments.

Abstract

The model underlying physics of guiding light in single-mode fibers -- the one-dimensional nonlinear Schr\"odinger equation (NLSE), reveals a remarkable balance of the fiber dispersion and nonlinearity, leading to the existence of optical solitons. With the Inverse Scattering Transform (IST) method and its perturbation theory extension one can go beyond single-soliton physics and investigate nonlinear dynamics of complex optical pulses driven by soliton interactions. Here, advancing the IST perturbation theory approach, we introduce the eigenvalue response functions, which provide an intuitively clear way to manipulate individual characteristics of solitons even in the case of their entire overlapping, i.e. very strong interactions. The response functions reveal the spatial sensitivity of the multi-soliton pulse concerning its instantaneous perturbations, allowing one to manipulate the velocities and amplitudes of each soliton. Our experimental setup, based on a recirculating optical fiber loop system and homodyne measurement, enables observation of long-distance NLSE dynamics and complete characterization of optical pulses containing several solitons. Adding a localized phase perturbation on a box-shaped wavefield, we change individual soliton characteristics and can detach solitons selectively from the whole pulse. The detached solitons exhibit velocities very close to the theoretical predictions, thereby demonstrating the efficiency and robustness of the response functions approach.