Overcoming the efficiency-bandwidth tradeoff for optical harmonics generation using nonlinear time-variant resonators

TL;DR

This paper demonstrates that time-varying resonant photonic structures can surpass the traditional efficiency-bandwidth tradeoff in optical harmonic generation by optimizing excitation and resonator dynamics.

Contribution

It introduces a novel approach using nonlinear time-variant resonators to enhance nonlinear optical processes beyond bandwidth limitations.

Findings

Time-varying resonators can outperform static cavities in nonlinear efficiency.

Optimized excitation and resonator evolution improve harmonic generation.

Conditions for surpassing cavity bandwidth are identified.

Abstract

Highly resonant photonic structures, such as cavities and metasurfaces, can dramatically enhance the efficiency of nonlinear processes by utilizing strong optical field enhancement at the resonance. The latter, however, comes at the expense of the bandwidth. Here, we overcome such tradeoff by utilizing time-varying resonant structures. Using harmonics generation as an example, we show that the amplitude and phase format of the excitation, as well as the time evolution of the resonator, can be optimized to yield the strongest nonlinear response. We find the conditions for an efficient synthesis of electromagnetic signals that surpass the cavity bandwidth, and discuss a potential experimental realization of this concept.