Omni-resonant space-time wave packets

TL;DR

This paper introduces a new class of diffraction-free, ultrashort space-time wave packets that can pass through Fabry-Perot resonators without spectral filtering, regardless of the cavity linewidth, maintaining their shape and bandwidth.

Contribution

It presents the theoretical description and experimental verification of Omni-resonant wave packets that couple to a single resonant mode independently of linewidth.

Findings

Wave packets retain their bandwidth and profile after passing through narrow linewidth cavities.

Omni-resonant wave packets couple to a single mode regardless of cavity linewidth.

Experimental results confirm diffraction-free and bandwidth-preserving transmission.

Abstract

We describe theoretically and verify experimentally a novel class of diffraction-free pulsed optical beams that are `Omni-resonant': they have the remarkable property of transmission through planar Fabry-Perot resonators without spectral filtering even if their bandwidth far exceeds the cavity resonant linewidth. Ultrashort wave packets endowed with a specific Spatio-temporal structure couple to a \textit{single} resonant mode independently of its linewidth. We confirm that such `space-time' Omni-resonant wave packets retain their bandwidth (1.6~nm), Spatio-temporal profile (1.3-ps pulse width, 4-$\mu$m beam width), and diffraction-free behavior upon transmission through cavities with resonant linewidths of 0.3-nm and 0.15-nm.