Three-Octave Supercontinuum Generation Spanning from Ultraviolet in Lithium Tantalate Waveguides

We demonstrate, for the first time, supercontinuum generation spanning more than three octaves in dispersion-engineered thin-film lithium tantalate (TFLT) waveguides. Pumped by a femtosecond laser at 1560 nm, the waveguides yield a spectrum from 240 nm in the ultraviolet to beyond 2400 nm in the near-infrared. The spectral evolution is mapped from low-power harmonic generation (second- and third-harmonic) to a high-power continuum driven by soliton fission and dispersive wave emission. This first demonstration of ultrabroadband nonlinear optics in TFLT establishes it as a competitive, low-loss platform for integrated photonics, with significant potential for applications in frequency metrology and on-chip spectroscopy.