Energy and Power requirements for alteration of the refractive index

TL;DR

This paper compares the energy and power requirements of various methods for altering the refractive index, highlighting that the choice of scheme significantly impacts power consumption more than the material used.

Contribution

It provides a comprehensive analysis of the energy and power trade-offs in different refractive index modulation techniques, emphasizing the influence of the modulation scheme over material properties.

Findings

Power consumption varies greatly across techniques.

Material choice has less impact on power reduction.

Resonant and traveling wave schemes significantly influence interaction time.

Abstract

The ability to manipulate the refractive index is a fundamental principle underlying numerous photonic devices. Various techniques exist to modify the refractive index across diverse materials, making performance comparison far from straightforward. In evaluating these methods, power consumption emerges as a key performance characteristic, alongside bandwidth and footprint. Here I undertake a comprehensive comparison of the energy and power requirements for the most well-known index change schemes. The findings reveal that while the energy per volume for index change remains within the same order of magnitude across different techniques and materials, the power consumption required to achieve switching, 100% modulation, or 100% frequency conversion can differ significantly, spanning many orders of magnitude. As it turns out, the material used has less influence on power reduction than the specific resonant or traveling wave scheme employed to enhance the interaction time between light and matter. Though this work is not intended to serve as a design guide, it does establish the limitations and trade-offs involved in index modulation, thus providing valuable insights for photonics practitioners.