Large Pitch Kagome-Structured Hollow-Core PCF

The difficulties in fabricating low loss photonic band gap PCF based on triangular lattice (T-PBGF) (Smith er al., 2003) for operation in the visible spectrum and the intrinsically narrow transmission bandwidth of these fibres exclude their implementation in broadband optical guidance applications in this spectral region. The large pitch ( Lambda ~ 12 mum) Kagome structured fibre reported here has the potential to lift these limitations and opens new perspectives for gas-laser applications such as high harmonic generation or broadband stimulated Raman scattering for nonlinear optics and many applications in quantum optics. Thanks to a pitch larger than previous Kagome fibres (Benabid et al., 2002), the fibre operates at high normalized frequency kLambda (k: propagation constant), never investigated before.