Mode pumping in photonic lattices using a single tailored auxiliary waveguide

TL;DR

This paper introduces a versatile method to excite and transfer topological and bulk modes in photonic lattices using a single auxiliary waveguide with controlled parameters, achieving high purity and experimental feasibility.

Contribution

A novel approach to pump and transfer modes in photonic lattices via a single tailored auxiliary waveguide, enabling efficient mode control and conversion.

Findings

Purities above 99% achieved in mode pumping.

Method applicable to topological and bulk modes.

Experimental parameter ranges are feasible.

Abstract

In this work, we propose a completely general method to pump the gapped topological modes of a lattice of optical waveguides by controlling the propagation constant of an auxiliary waveguide and its coupling to the main lattice. In this way, we can transform a single-waveguide excitation on the auxiliary waveguide into a specific mode of the lattice. We also demonstrate the possibility of transferring supermodes between two waveguide lattices using the same method. We illustrate the results by pumping and transferring the topological modes of Su-Schrieffer-Heeger lattices. For both scenarios, we show that purities above 99\% can be achieved with parameter values within experimental reach. Additionally, we demonstrate how the technique can be used to pump the bulk modes of the lattice for low number of waveguides or enable mode conversion between waveguide lattices.