Ultraviolet-C to mid-infrared supercontinuum generation in periodically poled lithium tantalate waveguides

Xiong et al. Light: Science & Applications (2026)15:253 https://doi.org/10.1038/s41377-026-02323-4 www.nature.com/lsa ARTICLE Open Access Ultraviolet-C to mid-infrared supercontinuum generation in periodically poled lithium tantalate waveguides 1234567890():,; 1234567890():,; 1234567890():,; 1234567890():,; Hongzhi Xiong1, Xinmin Yao1, Ming Zhang1,2 ✉, Qingrui Yao1, Huan Li Yaocheng Shi 1, Hon-ki Tsang 3 and Daoxin Dai 1,2,4 ✉ 1 , Zejie Yu 1 , Gong Zhang 1 , Liu Liu 1 , Abstract Supercontinuum generation makes use of the nonlinear optical effects arising from the interaction of light with the bound electronic states in crystal lattices and has many applications, especially in the ultraviolet for the direct probing of large-energy electronic transitions. However, supercontinuum from integrated waveguides has been limited to >330 nm in the ultraviolet-A band because of material dispersion and absorption. Here, we demonstrate unprecedented ultraviolet-C-to-mid-infrared supercontinuum on a chip, leveraging the exceptional transparency window and second-order nonlinearity of lithium tantalate (LT). A key innovation is the introduction of chirped periodically poled LT with submicron ferroelectric domains. Utilizing 3-wave-mixing processes under quasi-phasematching conditions, we created the shortest ultraviolet wavelength ever reported from a chip—below 270 nm— while reaching 2400 nm in the mid-infrared, covering more than three octaves with just 100 pJ pulse energy on a chip for the first time. It’s the first on-chip supercontinuum fully covering the ultraviolet-A/B bands while extending into the ultraviolet-C band. This work establishes thin-film LT as a versatile platform for full-spectrum nonlinear photonics, opening new possibilities for integrated ultraviolet sources. Introduction Supercontinuum generation (SCG) is a nonlinear process in which an ultrashort and intense optical pulse undergoes significant spectral broadening during its propagation in nonlinear optical materials. In particular, ultraviolet SCG (UV-SCG) has emerged as a transformative technology for precision spectroscopy and fundamental physics, enabling direct probing of electronic transitions through broadband spectral coverage below 400 nm1–3. The unique combination of ultra-short pulse duration, high peak power, and inherent phase coherence positions UV-SCG as a critical enabler for next- Correspondence: Ming Zhang () or Daoxin Dai () 1 State Key Laboratory for Extreme Photonics and Instrumentation, Zhejiang Key Laboratory of Optoelectronic Information Technology, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Zijingang Campus, Hangzhou, China 2 Ningbo Global Innovation Center, Zhejiang University, Ningbo, China Full list of author information is available at the end of the article These authors contributed equally: Hongzhi Xiong, Xinmin Yao. generation applications such as nuclear clock transitions4 and astronomical spectrograph calibration5. Particularly charming is its potential to extend frequency combs into the UV regime, bridging critical gaps in optical metrology and quantum control of atomic systems5–7. Supercontinuum generation in optical fibers has been extensively explored and widely applied owing to their low transmission loss and flexible dispersion engineering8–11. The maturation of high-nonlinearity fiber and crystal fiber fabrication technologies has greatly accelerated the development of supercontinuum, enabling fiber-based supercontinuum generation across the visible, near-infrared, and mid-infrared spectral regions. Recent advances have further extended fiber-based supercontinuum into the ultraviolet region12–15. These explorations of nonlinear frequency generation in the ultraviolet regime have played a pivotal role in advancing broadband ultraviolet light sources and spectroscopic sensing. In contrast to traditional SCG based on fiber and bulk nonlinear optics16–18, on-chip SCG has emerged as a © The Author(s) 2026 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Xiong et al. Light: Science & Applications (2026)15:253 key research focus1,19 to achieve highly compact supercontinuum sources with a footprint in mm2-scale20. Moreover, building upon the established foundation of on-chip photonic components such as optical filters21, optical modulators22, and optical sensing waveguides23,24, further developments are expected to enable monolithic integration of SCG with other specific modules for satisfy the demands of various applications25,26. Although nanophotonic architectures leveraging tight mode confinement and dispersion engineering have revolutionized SCG in the infrared1,19,27, on-chip SCG extended to cover the UV-band still faces fundamental limitations from the intrinsic properties of conventional photonic materials. First, most integrated photonic materials exhibit prohibitive UV absorption at wavelengths below 350 nm. Second, the strong normal dispersion at the UV band for the femtosecond pump fundamentally disrupts the parametric processes through phase mismatch2,6. Recent attempts to circumvent these challenges through the second-order nonlinearity in aluminum nitride (AlN)6,28,29 and lithium niobate (LN)7,30 waveguides have achieved partial success by utilizing 3wave-mixing (3WM) or cascaded 3WM. This is helpful to enhance the wavelengths in the visible and UV range, while the intrinsic material constraint remains. One should note that, AlN’s weak second-order nonlinearity with χ²~4.7 pm/V necessitates the use of extremely large pump intensities for efficient frequency conversion6,28,29, while LN’s UV absorption edge near 330 nm fundamentally limits spectral extension even though it has a high nonlinear coefficient (χ² ~ 25 pm/V)31 and also supports quasi-phase-matching (QPM) for 3WM7,30. Besides, in order to satisfy the phase matching condition, the UV and near-UV light of the SCG on SiN32 and AlN2,6,28,29 is often carried by the higher-order modes, which is not preferred when it is desired to integrate the SCG sources with other specific modules on a chip. Instead, the SCG is desired to operate with the f (...truncated)