Multimode nonlinear & quantum optics

There has recently been a renewed interest in the study and exploitation of the spatial degrees of freedom in confined waveguide geometries. Broadband-guiding hollow-core fibres are excellent platforms for this purpose since they are inherently multimode structures where each transverse mode features distinct spatial profile and dispersion. The latter knob can be thereby tuned to allow for phase-matched, efficient nonlinear conversion of intense laser light travelling through the central hollow channel of the fibre.

We try to exploit this capability of hollow waveguides to design novel strategies for frequency conversion of coherent light in fully collinear geometries, where the phase-velocity mismatch inherent to all parametric nonlinear interactions can be mitigated using different fibre modes. Along the same lines, we are also interested in the manipulation of quantum light sources such as biphotons, whose delicate quantum correlations can be tailored and preserved over long distances under the right conditions.