Nonlinear performance of asymmetric coupler based on dual-core photonic crystal fiber: towards sub-nanojoule solitonic ultrafast all-optical switching

TL;DR

This paper demonstrates ultrafast, sub-nanojoule energy level soliton-based nonlinear balancing in dual-core photonic crystal fibers, enabling high-contrast all-optical switching with potential for ultrafast photonic devices.

Contribution

It introduces a novel experimental and numerical study of nonlinear asymmetry balancing in dual-core fibers at sub-nanojoule energies, advancing ultrafast all-optical switching technology.

Findings

High energy transfer rate observed in nonlinear asymmetry balancing.

Narrow band spectral switching with 23 dB contrast at 1800 nm.

Switching achieved with sub-nanojoule pulse energies.

Abstract

We demonstrate ultrafast soliton-based nonlinear balancing of dual-core asymmetry in highly nonlinear photonic crystal fiber at sub-nanojoule pulse energy level. The effect of fiber asymmetry was studied experimentally by selective excitation and monitoring of individual fiber cores at different wavelengths between 1500 nm and 1800 nm. Higher energy transfer rate to non-excited core was observed in the case of fast core excitation due to nonlinear asymmetry balancing of temporal solitons, which was confirmed by the dedicated numerical simulations based on the coupled generalized nonlinear Schr\"odinger equations. Moreover, the simulation results correspond qualitatively with the experimentally acquired dependences of the output dual-core extinction ratio on excitation energy and wavelength. In the case of 1800 nm fast core excitation, narrow band spectral intensity switching between the output channels was registered with contrast of 23 dB. The switching was achieved by the change of the excitation pulse energy in sub-nanojoule region. The performed detailed analysis of the nonlinear balancing of dual-core asymmetry in solitonic propagation regime opens new perspectives for the development of ultrafast nonlinear all-optical switching devices.