Near-zero-index ultra-fast pulse characterization

Wallace Jaffray, Federico Belli, Enrico Giuseppe Carnemolla, Catalina Dobas, Mark Mackenzie, John Travers, Ajoy Kumar Kar, Matteo Clerici, Clayton DeVault, Vladimir M. Shalaev, Alexandra Boltasseva, Marcello Ferrera

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)
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Transparent conducting oxides exhibit giant optical nonlinearities in the near-infrared window where their linear index approaches zero. Despite the magnitude and speed of these nonlinearities, a “killer” optical application for these compounds has yet to be found. Because of the absorptive nature of the typically used intraband transitions, out-of-plane configurations with short optical paths should be considered. In this direction, we propose an alternative frequency-resolved optical gating scheme for the characterization of ultra-fast optical pulses that exploits near-zero-index aluminium zinc oxide thin films. Besides the technological advantages in terms of manufacturability and cost, our system outperforms commercial modules in key metrics, such as operational bandwidth, sensitivity, and robustness. The performance enhancement comes with the additional benefit of simultaneous self-phase-matched second and third harmonic generation. Because of the fundamental importance of novel methodologies to characterise ultra-fast events, our solution could be of fundamental use for numerous research labs and industries.
Original languageEnglish
Article number3536
JournalNature Communications
Publication statusPublished - 20 Jun 2022


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