Enhancement of transmission quality in soliton-based optical waveguide systems by frequency dependent linear gain-loss and the Raman self-frequency shift

TL;DR

This paper demonstrates that frequency dependent linear gain-loss combined with Raman effects significantly improves transmission quality in soliton-based optical waveguides by suppressing radiation emission, unlike frequency independent gain-loss.

Contribution

It introduces a novel approach using frequency dependent gain-loss and Raman effects to enhance transmission stability in nonlinear optical waveguides.

Findings

Frequency dependent gain-loss suppresses radiation emission effectively.

Raman self-frequency shift separates soliton spectrum from radiation.

Enhanced transmission quality similar to waveguides with guiding filters.

Abstract

We study transmission stabilization against radiation emission in soliton-based nonlinear optical waveguides with weak linear gain-loss, cubic loss, and delayed Raman response. We show by numerical simulations with perturbed nonlinear Schr\"odinger propagation models that transmission quality in waveguides with frequency independent linear gain and cubic loss is not improved by the presence of delayed Raman response due to the lack of an efficient mechanism for suppression of radiation emission. In contrast, we find that the presence of delayed Raman response leads to significant enhancement of transmission quality in waveguides with frequency dependent linear gain-loss and cubic loss. Enhancement of transmission quality in the latter waveguides is enabled by the separation of the soliton's spectrum from the radiation's spectrum due to the Raman-induced self-frequency shift and by efficient suppression of radiation emission due to the frequency dependent linear gain-loss. Further numerical simulations demonstrate that the enhancement of transmission quality in waveguides with frequency dependent linear gain-loss, cubic loss, and delayed Raman response is similar to transmission quality enhancement in waveguides with linear gain, cubic loss, and guiding filters with a varying central frequency.