Ultraviolet to Mid-Infrared Supercontinuum Generation in Photonic Crystal Fibers

This work conducts a comparative study of the different mechanisms involved in supercontinuum generation in photonic crystal fibers (PCFs) when pumped within the normal and anomalous dispersion regimes. A femtosecond laser operating at 1030 nm was employed to pump both a commercial PCF with a zero-dispersion wavelength (ZDW) of 1210 nm and a custom-fabricated PCF exhibiting a ZDW of 916 nm. The findings indicate that pumping in the anomalous dispersion region elicits pronounced nonlinear effects. Using the custom-designed PCF, an ultra-broadband spectrum spanning 350–2100 nm was achieved, demonstrating spectral broadening markedly superior to that observed in the commercial PCF pumped in the normal dispersion region. This work not only realized a supercontinuum extending nearly three octaves from the ultraviolet to the mid-infrared through tailored design of the PCF's air-hole array structure but also revealed the critical role of the pump dispersion region in nonlinear processes and spectral broadening, providing important references for customizing high-performance supercontinuum sources.