ACS Photon. https://doi.org/c35s (2019)
A miniature broadband deep-ultraviolet light source that emits from 240 to 300 nm has been demonstrated by scientists in Germany and the United States. Liping Shi and colleagues make use of third-harmonic generation (THG) in rectangular nanoholes in a gold film. Localized surface plasmon modes in the holes were excited by a broadband Ti:sapphire oscillator emitting ultrashort pulses centred at 825 nm wavelength. The plasmon resonances not only boost the third-harmonic intensity, but also enable it to be broadened to a spectral width of 60 nm. The structure consisted of 290 nm × 140 nm apertures in a 250-nm-thick Au film on 15-nm silicon nitride, arrayed with 42-nm period over a 50 × 50 μm2 area. Plasmonic resonances at ~760 nm and ~820 nm wavelength were identified as being responsible for the efficient widening of the response. The THG conversion efficiency is of the order of 10−9 and third-harmonic output is elliptically polarized.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Pile, D.F.P. Broadband UV source. Nat. Photonics 13, 303 (2019). https://doi.org/10.1038/s41566-019-0430-6
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41566-019-0430-6