Broadband ultraviolet-visible frequency combs from cascaded high-harmonic generation in quasi-phase-matched waveguides

Published

July 7, 2021

Author(s)

Scott Diddams, Jay Rutledge, Anthony Catanese, Daniel Hickstein, Thomas K. Allison, Abijith Kowligy

Abstract

High-harmonic generation (HHG) provides short-wavelength light that is useful for precision spectroscopy and probing ultrafast dynamics. Here, we report ecient, phase-coherent harmonic generation up to 9th-order (333 nm) in chirped periodically poled lithium niobate waveguides driven by phase-stable 12-nJ, 100 fs pulses at 3 \mum, with 100 MHz repetition rate. A mid-infrared to ultraviolet-visible conversion efficiency as high as 10% is observed, amongst an overall 23% conversion of the fundamental to all harmonics. We verify the coherence of the harmonic frequency combs despite the complex highly nonlinear process. Numerical simulations based on a single broadband envelope equation with second-order nonlinearity give estimates for the conversion efficiency within approximately 1 order of magnitude over a wide range of experimental parameters. From this comparison we identify a dimensionless parameter, capturing the competition between group-velocity walkoff of the harmonics and three-wave mixing, that governs the cascaded HHG physics. These results can inform cascaded HHG in a range of different platforms.

Citation

The Journal of Optical Society of America B

Volume

38

Pub Type

Journals

Download Paper

https://doi.org/10.1364/JOSAB.427086

Local Download

Keywords

frequency comb, nonlinear optics, spectroscopy

Citation

Diddams, S. , Rutledge, J. , Catanese, A. , Hickstein, D. , Allison, T. and Kowligy, A. (2021), Broadband ultraviolet-visible frequency combs from cascaded high-harmonic generation in quasi-phase-matched waveguides, The Journal of Optical Society of America B, [online], https://doi.org/10.1364/JOSAB.427086, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931935 (Accessed October 11, 2025)