UV-Grade Silica-Based Photonic Crystal Fibers for Broadband UV Generation over 350–395 nm

A major challenge in supercontinuum (SC) generation is to overcome the shortcomings of existing fibre-based SC sources in the ultraviolet (UV) wavelength range below 400 nm [1]. There is particular need for broadband sources of UV light in applications such as multi-photon fluorescence microscopy for simultaneous coherent excitation of multiple fluorophores. However, UV generation in conventional silica-core fibres is extremely difficult because of factors such as material absorption, large normal dispersion, glass stability, power handling, and aging, and this has motivated much recent interest in the use of alternative approaches [2,3]. Although these results show great promise, compatibility with the ubiquitous silica platform remains a problem, and there is thus intense current interest in generating UV-light using modified UV-resistant silica glasses.