On-Chip Phase-Shift Induced Control of Supercontinuum Generation in a Dual-Core Si$\mathbf{_{3}}$N$\mathbf{_{4}}$ Waveguide

TL;DR

This paper demonstrates on-chip spectral control of supercontinuum generation in dual-core Si3N4 waveguides by phase-shifting to selectively excite supermodes, enabling tunable dispersion and diverse spectra.

Contribution

It introduces a method to control supercontinuum spectra on-chip using phase-shift induced supermode excitation in dual-core waveguides, a novel approach for spectral engineering.

Findings

Selective supermode excitation varies dispersion from all-normal to anomalous.

Phase shifting in Mach-Zehnder circuits enables spectral control.

Different supercontinuum spectra achieved with the same waveguide design.

Abstract

We investigate on-chip spectral control of supercontinuum generation, taking advantage of the additional spatial degree of freedom in strongly-coupled dual-core waveguides. Using numerical integration of the multi-mode generalized nonlinear Schr\"odinger equation, we show that, with proper waveguide cross-section design, selective excitation of supermodes can vary the dispersion to its extremes, i.e., all-normal or anomalous dispersion can be selected via phase shifting in a Mach-Zehnder input circuit. The resulting control allows to provide vastly different supercontinuum spectra with the same waveguide circuit.