Adiabatic frequency shifting in epsilon near zero materials: The role of group velocity

TL;DR

This paper explores adiabatic frequency shifting in epsilon near zero materials, revealing that efficient conversion can be achieved with shorter lengths and lower pump intensities due to slow light effects, without complex nanofabrication.

Contribution

It demonstrates that ENZ materials enable efficient adiabatic frequency conversion with reduced device size and pump power, leveraging slow propagation effects.

Findings

Maximum frequency conversion does not increase near epsilon=0.

Conversion efficiency in ENZ materials is comparable to microresonators.

No nanofabrication is needed for ENZ-based frequency conversion.

Abstract

We investigate adiabatic frequency conversion using epsilon near zero (ENZ) materials and show that while the maximum frequency conversion for a given change of permittivity does not exhibit increase in the vicinity of {\epsilon}=0 condition. However, that change can be achieved in a shorter length, and if the pump is also in the ENZ vicinity, at a lower pump intensity. This slow propagation effect makes the conversion efficiency in the ENZ material comparable to that in microresonators and other structured slow light schemes, but unlike the latter no nanofabrication is required for ENZ materials which constitutes their major advantage over alternative frequency conversion approaches.