Inverse design of optical pulse shapes for time-varying photonics

TL;DR

This paper introduces a novel inverse design method for optical pulse shapes to improve their interaction with time-varying media, achieving significant broadband transmission enhancements without changing pulse energy.

Contribution

The paper presents a new inverse design approach for tailoring optical pulses to optimize their transmission through time-varying media, including gain and ENZ materials.

Findings

Achieved large broadband enhancements in pulse transmission.

Demonstrated increased transmittance through pumped indium tin oxide.

Validated the effectiveness of the inverse design method in complex media.

Abstract

There has been an explosion of interest in time-varying photonics due to the recent discovery and design of materials and metamaterials with strong, time-varying, nonlinear optical responses. This opens the door to novel optical phenomena including reciprocity breaking, frequency translation, and amplification that can be enhanced by optimizing the light-matter interaction. Although there has been recent interest in applying topology-based inverse design to this problem, we have decided to take a more novel approach. In this article, we will introduce a method for the inverse design of optical pulse shapes to enhance their interaction with time-varying media. We test our objective-first approach by maximizing the transmittance of optical pulses of equal intensity through time-varying media. Indeed, without requiring a change in pulse energy, we demonstrate large, broadband enhancements in the pulse energy transmission through the thin-films, including gain. Our final test includes maximizing pulse transmission through indium tin oxide, a time-varying medium when strongly pumped in its ENZ band. Through this work, we hope to inspire exploration of this new degree of freedom.