Omni-resonant space-time wave packets

We describe theoretically and verify experimentally a novel, to the best of our knowledge, 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 linewidth. Ultrashort wave packets endowed with a specific spatiotemporal structure couple to a single resonant mode independent of its linewidth. We confirm that such space-time omniresonant wave packets retain their bandwidth (1.6 nm), spatiotemporal 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. (C) 2020 Optical Society of America