Programmable omni-resonance using space–time fields

Abstract

Omni-resonant wave packets are pulsed optical beams that couple to planar cavities even when the wave packet bandwidth far exceeds the cavity resonant linewidth by virtue of a precise spatiotemporal structure introduced into the optical field. We demonstrate experimentally the synthesis of programmable omni-resonant wave packets in which a prescribed pulse spectrum is made to resonate with a planar cavity. Examples include controllable-bandwidth resonant spectral lines, spectral holes with tunable notch bandwidth, and even arbitrary resonant spectra. These novel resonant interactions are realized with no changes made to the cavity itself, and therefore, without compromising its quality factor—only sculpting the spatiotemporal spectrum of the incident field is required. Programmable omni-resonance allows harnessing resonant field enhancements over arbitrary spectral profiles without restriction to traditionally narrow resonant linewidths.