Tailored Periodically-Poled Lithium Niobate Waveguides for Highly Efficient Broadband Supercontinuum Generation

Broadband supercontinuum generation is one of the most exploited effects of nonlinear optics as it enables applications in medicine, metrology, astronomy and elsewhere. Recently, integrated platforms such as lithium niobate-on-insulator (LNOI), have demonstrated the potential to dramatically increase the efficiency of such applications [1]–[3]. This increase in efficiency is not only due to their higher mode confinement, leading to enhanced nonlinear processes, but also the ability to generate tailored spectra through dispersion engineering and quasi phase matching with periodic poling. However, unlocking the full potential of LNOI requires a dedicated fabrication process. To ensure mode confinement in broad spectral range, one needs to etch the lithium niobate entirely, often a difficult task. Similarly, a dedicated periodic poling process is needed for the wide range of phase matching conditions when transferring a broad spectrum with harmonics generation.