Scattering of a cross-polarized linear wave by a soliton at an optical event horizon in a birefringent nanophotonic waveguide

TL;DR

This paper investigates how a cross-polarized linear wave interacts with a soliton at an optical event horizon in a birefringent nanophotonic waveguide, revealing nearly wavelength-independent frequency conversion.

Contribution

It provides the first combined experimental and numerical analysis of cross-polarized wave scattering at an optical event horizon in integrated birefringent waveguides, highlighting unique frequency conversion properties.

Findings

Idler frequency shifts only 10 nm around 1550 nm

Frequency conversion is nearly independent of soliton wavelength

Experimental results are supported by full vectorial simulations

Abstract

The scattering of a linear wave on an optical event horizon, induced by a cross polarized soliton, is experimentally and numerically investigated in integrated structures. The experiments are performed in a dispersion-engineered birefringent silicon nanophotonic waveguide. In stark contrast with co-polarized waves, the large difference between the group velocity of the two cross-polarized waves enables a frequency conversion almost independent on the soliton wavelength. It is shown that the generated idler is only shifted by 10 nm around 1550 nm over a pump tuning range of 350 nm. Simulations using two coupled full vectorial nonlinear Schr\"odinger equations fully support the experimental results.