Enhancing second harmonic generation by Q-boosting lossless cavities beyond the time bandwidth limit

Abstract: Nanostructures proved to be versatile platforms to control the electromagnetic field at subwavelength scale. Indeed, high-quality-factors nanocavities have been used to boost and control nonlinear frequency generation by increasing the light–matter interaction. However, nonlinear processes are triggered by high-intensities, which are provided by ultrashort laser pulses with large bandwidth, which cannot be fully exploited in such devices. Time-varying optical systems allow one to overcome the time-bandwidth limit by modulating the cavity external coupling. Here we present a general treatment, based on coupled mode theory, to describe second harmonic generation in a doubly resonant cavity for which the quality-factor at the fundamental frequency is modulated in time. We identify the initial quality factor maximizing second harmonic efficiency when performing Q-boosting and we predict a theoretical energy conversion efficiency close to unity. Our results have direct impact on the design of next generation time-dependent metasurfaces to boost nonlinear frequency conversion of ultrashort laser pulses.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Enhancing second harmonic generation by Q-boosting lossless cavities beyond the time bandwidth limit ; volume:13 ; number:1 ; year:2024 ; pages:1-8 ; extent:8 ; Nanophotonics ; 13, Heft 1 (2024), 1-8 (gesamt 8)

Contributors, Places and Time

• Creator: Franceschini, Paolo ; Tognazzi, Andrea ; Chernyak, Anna M. ; Musorin, Alexander I. ; Cino, Alfonso C. ; Fedyanin, Andrey A. ; De Angelis, Costantino

Further information

• DOI: 10.1515/nanoph-2023-0389
• URN: urn:nbn:de:101:1-2024011713050113992853
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:27 AM CEST