Suspended core fibers infiltrated with liquid crystals for supercontinuum generation

Nonlinear birefringent fibers are essential for polarization-maintaining supercontinuum generation, which is critical for applications such as spectroscopy and optical atomic clocks. However, conventional high-birefringence fibers typically rely on specialized geometries, such as "panda," "bow-tie" structures or elliptical cores, requiring complex fabrication processes and offering limited flexibility in controlling nonlinear propagation. To overcome these limitations, we numerically investigate supercontinuum generation in liquid-crystal-filled suspended-core fibers based on lead-bismuth-gallate (PBG) glass. By infiltrating nematic liquid crystals (5CB) into the cladding and applying an external electric field, the fibers exhibit strong and tunable birefringence, enabling distinct dispersion regimes for orthogonally polarized modes. The combination of high nonlinearity in PBG glass and high birefringence induced by 5CB enables polarization-maintained, octave-spanning supercontinuum generation (900 nm–2800 nm) driven by soliton dynamics in the anomalous dispersion regime, as well as all-normal-dispersion supercontinuum generation (1100 nm–2500 nm) with high coherence. Furthermore, the coupling angle between the input polarization and the principal birefringent axes is identified as an efficient parameter for tailoring spectral bandwidth, coherence, and polarization properties. These findings establish liquid-crystal-filled suspended-core fibers as a versatile and electrically tunable platform for supercontinuum generation, offering dynamic control over output light properties without requiring structural modification. This approach opens opportunities for compact, adaptive, and highly coherent broadband light sources for applications in spectroscopy, metrology, and nonlinear photonics.