Supercontinuum generation (SCG) on thin-film lithium niobate platforms has opened new opportunities for applications in spectroscopy, metrology, and signal processing. However, the strong material dispersion of lithium niobate limits spectral broadening toward shorter wavelengths, particularly in waveguides without engineered domain structures, thereby restricting efficient SCG in the ultraviolet-to-visible region. Here we propose and theoretically demonstrate a new approach to overcome this limitation by harnessing higher-order waveguide modes. We show that femtosecond pumping near the visible spectrum can excite soliton fission and dispersive wave radiation in higher-order modes, efficiently transferring pump energy toward shorter wavelengths. Numerical simulations reveal that, under appropriate waveguide design and femtosecond pumping at a center wavelength of 860 nm, the excitation of the ${\mathrm{TE}}_{10}$ mode enables broadband SCG spanning 430–1260 nm at a −30 dB level. Our findings offer a simple and effective strategy for chip-scale SCG in the visible regime and pave the way for compact short-wavelength coherent frequency comb sources.

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• Nonlinear optics
• Nonlinear waveguides
• Optical solitons
• Supercontinuum generation
• Third order nonlinear optical processes