Exotic Light Sources

Coherent light sources in spectral regions such as the deep and vacuum ultraviolet (300 – 100 nm) and mid-far infrared (3000 – 30000 nm) find important applications in multiple disparate fields such as spectroscopy, materials science, imaging or biomedicine. Most sources available are either complex, bulky, lack wideband tunability and/or deliver poor beam quality. More interestingly, radiation in the aforementioned spectral regions, especially in the form of ultrashort bursts of light, can hardly travel unchanged in free space, which has hampered progress in many fields.

Although waveguide-based approaches would be desirable, few if any materials are transparent and present a high damage threshold so as to constitute viable solutions to the generation and guidance of such electromagnetic radiation. Hollow-core microstructured fibres guiding broadband through anti-resonant reflection constitute an attractive alternative to other existing approaches. We strive to conceive, implement and optimise fibre-based solutions to this issue, exploiting nonlinear optical effects occurring in the central hollow channel of the fibre when filled with gas. In this regard, we aim at controlling all degrees of freedom of the confined radiation: Spectral centroid, bandwidth, intensity, spatio-temporal structure, polarization and orbital angular momentum.